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Stephen Robert Wagner

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DOI: 10.1103/physrevlett.109.101802
2012
Cited 667 times
Evidence for an Excess of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mover accent="true"><mml:mi>B</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mo>→</mml:mo><mml:msup><mml:mi>D</mml:mi><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mo>*</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mi>τ</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msub><mml:mover accent="true"><mml:mi>ν</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mi>τ</mml:mi></…
Based on the full BABAR data sample, we report improved measurements of the ratios R(D(*))=B(B[over ¯]→D(*)τ(-)ν[over ¯](τ))/B(B[over ¯]→D(*)ℓ(ℓ)(-)ν[over ¯](ℓ)), where ℓ is either e or μ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D)=0.440±0.058±0.042 and R(D(*))=0.332±0.024±0.018, which exceed the standard model expectations by 2.0σ and 2.7σ, respectively. Taken together, our results disagree with these expectations at the 3.4σ level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.
DOI: 10.1103/physrevd.88.072012
2013
Cited 541 times
Measurement of an excess of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mover accent="true"><mml:mi>B</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mo>→</mml:mo><mml:msup><mml:mi>D</mml:mi><mml:mrow><mml:mo mathvariant="bold" stretchy="false">(</mml:mo><mml:mo>*</mml:mo><mml:mo mathvariant="bold" stretchy="false">)</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mi>τ</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><mml:msub><mml:mover accent="true"><mml:mi>ν…
Based on the full BaBar data sample, we report improved measurements of the ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or mu. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) = 0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0 sigma and 2.7 sigma, respectively. Taken together, our results disagree with these expectations at the 3.4 sigma level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. Kinematic distributions presented here exclude large portions of the more general type III two-Higgs-doublet model, but there are solutions within this model compatible with the results.
DOI: 10.1103/physrevd.80.052002
2009
Cited 284 times
Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>γ</mml:mi><mml:msup><mml:mi>γ</mml:mi><mml:mo>*</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>transition form factor
We study the reaction e+e- --> e+e-pi0 and measure the gamma gamma* --> pi0 transition form factor in the momentum transfer range from 4 to 40 GeV^2. The analysis is based on 442 fb^-1 of integrated luminosity collected at PEP-II with the BABAR detector at e+e- center-of-mass energies near 10.6 GeV.
DOI: 10.1103/physrevd.82.011101
2010
Cited 149 times
Evidence for the decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>X</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>3872</mml:mn><mml:mo stretchy="false">)</mml:mo><mml:mo>→</mml:mo><mml:mi>J</mml:mi><mml:mo>/</mml:mo><mml:mi>ψ</mml:mi><mml:mi>ω</mml:mi></mml:math>
We present a study of the decays B^{0,+} --> J/psi pi^+ pi^- pi^0 K^{0,+}, using 467 10^6 BBbar pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) --> J/psi omega, with product branching fractions B(B^+ --> X(3872)K^+) B(X(3872) --> J/psi omega) =[0.6\pm0.2\stat \pm 0.1\syst ] 10^{-5}, and B(B^0 --> X(3872)K^0) B(X(3872) --> J/psi omega) =[0.6\pm0.3\stat \pm 0.1\syst ] 10^{-5}. A detailed study of the pi^+ pi^- pi^0 mass distribution from X(3872) decay favors a negative-parity assignment.
DOI: 10.1103/physrevd.86.032012
2012
Cited 147 times
Measurement of branching fractions and rate asymmetries in the rare decays<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mo>*</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mi>ℓ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>ℓ</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>
In a sample of 471 million BB events collected with the BABAR detector at the PEP-II e+e- collider we study the rare decays B -> K(*) l+ l-, where l+ l- is either e+e- or mu+mu-. We report results on partial branching fractions and isospin asymmetries in seven bins of di-lepton mass-squared. We further present CP and lepton-flavor asymmetries for di-lepton masses below and above the J/psi resonance. We find no evidence for CP or lepton-flavor violation. The partial branching fractions and isospin asymmetries are consistent with the Standard Model predictions and with results from other experiments.
DOI: 10.1103/physrevlett.109.211801
2012
Cited 132 times
Observation of Time-Reversal Violation in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>Meson System
Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states (B(0) or B(0)), and J/ψK(L)(0) or ccK(S)(0) final states (referred to as B(+) or B(-)), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, B(0) → B(-) and B(-) → B(0), as a function of the time difference between the two B decays. Using 468 × 10(6) BB pairs produced in Υ(4S) decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding ΔS(T)(+) = -1.37 ± 0.14(stat) ± 0.06(syst) and ΔS(T)(-) = 1.17 ± 0.18(stat) ± 0.11(syst). These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.
DOI: 10.1103/physrevd.94.011102
2016
Cited 126 times
Search for a muonic dark force at<i>BaBar</i>
Many models of physics beyond the standard model predict the existence of new Abelian forces with new gauge bosons mediating interactions between ``dark sectors'' and the standard model. We report a search for a dark boson ${Z}^{\ensuremath{'}}$ coupling only to the second and third generations of leptons in the reaction ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}{Z}^{\ensuremath{'}},{Z}^{\ensuremath{'}}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ using $514\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data collected by the BABAR experiment. No significant signal is observed for ${Z}^{\ensuremath{'}}$ masses in the range 0.212--10 GeV. Limits on the coupling parameter ${g}^{\ensuremath{'}}$ as low as $7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ are derived, leading to improvements in the bounds compared to those previously derived from neutrino experiments.
DOI: 10.1103/physrevd.83.032007
2011
Cited 115 times
Study of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:mi>π</mml:mi><mml:mi>l</mml:mi><mml:mi>ν</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:mi>ρ</mml:mi><mml:mi>l</mml:mi><mml:mi>ν</mml:mi></mml:math>decays and determination of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mo stretchy="false">|</mml:mo><…
We present an analysis of exclusive charmless semileptonic $B$-meson decays based on $377\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs recorded with the BABAR detector at the $\mathit{\ensuremath{\Upsilon}}(4S)$ resonance. We select four event samples corresponding to the decay modes ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, and ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$ and find the measured branching fractions to be consistent with isospin symmetry. Assuming isospin symmetry, we combine the two $B\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\ell}\ensuremath{\nu}$ samples, and similarly the two $B\ensuremath{\rightarrow}\ensuremath{\rho}\ensuremath{\ell}\ensuremath{\nu}$ samples, and measure the branching fractions $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu})=(1.41\ifmmode\pm\else\textpm\fi{}0.05\ifmmode\pm\else\textpm\fi{}0.07)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu})=(1.75\ifmmode\pm\else\textpm\fi{}0.15\ifmmode\pm\else\textpm\fi{}0.27)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, where the errors are statistical and systematic. We compare the measured distribution in ${q}^{2}$, the momentum transfer squared, with predictions for the form factors from QCD calculations and determine the Cabibbo-Kobayashi-Maskawa matrix element $|{V}_{ub}|$. Based on the measured partial branching fraction for $B\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\ell}\ensuremath{\nu}$ in the range ${q}^{2}&lt;12\text{ }\text{ }{\mathrm{GeV}}^{2}$ and the most recent QCD light-cone sum-rule calculations, we obtain $|{V}_{ub}|=(3.78\ifmmode\pm\else\textpm\fi{}{0.13}_{\ensuremath{-}0.40}^{+0.55})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, where the errors refer to the experimental and theoretical uncertainties. From a simultaneous fit to the data over the full ${q}^{2}$ range and the FNAL/MILC lattice QCD results, we obtain $|{V}_{ub}|=(2.95\ifmmode\pm\else\textpm\fi{}0.31)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ from $B\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\ell}\ensuremath{\nu}$, where the error is the combined experimental and theoretical uncertainty.
DOI: 10.1103/physrevd.89.111103
2014
Cited 81 times
Study of the reaction<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:mi>ψ</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>2</mml:mn><mml:mi>S</mml:mi><mml:mo stretchy="false">)</mml:mo><mml:msup><mml:mrow><mml:mi>π</mml:mi…
We study the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\psi}(2S){\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BABAR detector at center-of-mass energies at and near the $\mathrm{\ensuremath{\Upsilon}}(\mathrm{nS})$ ($n=2,3,4$) resonances and correspond to an integrated luminosity of $520\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. We investigate the $\ensuremath{\psi}(2S){\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ mass distribution from 3.95 to $5.95\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, and measure the center-of-mass energy dependence of the associated ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\psi}(2S){\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ cross section. The mass distribution exhibits evidence of two resonant structures. A fit to the $\ensuremath{\psi}(2S){\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ mass distribution corresponding to the decay mode $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}J/\ensuremath{\psi}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ yields a mass value of $4340\ifmmode\pm\else\textpm\fi{}16\text{ }(\text{stat})\text{ }\ifmmode\pm\else\textpm\fi{}9\text{ }(\text{syst})\text{ }\text{ }\mathrm{MeV}/{c}^{2}\text{ }$ and a width of $94\ifmmode\pm\else\textpm\fi{}32\text{ }(\text{stat})\text{ }\ifmmode\pm\else\textpm\fi{}13\text{ }(\text{syst})\text{ }\text{ }\mathrm{MeV}$ for the first resonance, and for the second a mass value of $4669\ifmmode\pm\else\textpm\fi{}21\text{ }(\text{stat})\text{ }\ifmmode\pm\else\textpm\fi{}3\text{ }(\text{syst})\text{ }\text{ }\mathrm{MeV}/{c}^{2}\text{ }$ and a width of $104\ifmmode\pm\else\textpm\fi{}48\text{ }(\text{stat})\text{ }\ifmmode\pm\else\textpm\fi{}10\text{ }(\text{syst})\text{ }\text{ }\mathrm{MeV}$. In addition, we show the ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ mass distributions for these resonant regions.
DOI: 10.1103/physrevd.86.092004
2012
Cited 91 times
Branching fraction and form-factor shape measurements of exclusive charmless semileptonic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>decays, and determination of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mo stretchy="false">|</mml:mo><mml:msub><mml:mi>V</mml:mi><mml:mrow><mml:mi>u</mml:mi><mml:mi>b</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">|</mml:mo></mml:math>
We report the results of a study of the exclusive charmless semileptonic decays, ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\omega}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\eta}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, and ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$ ($\ensuremath{\ell}=e$ or $\ensuremath{\mu}$) undertaken with approximately $462\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the BABAR detector. The analysis uses events in which the signal $B$ decays are reconstructed with a loose neutrino reconstruction technique. We obtain partial branching fractions in several bins of ${q}^{2}$, the square of the momentum transferred to the lepton-neutrino pair, for ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\omega}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$, and ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\eta}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$. From these distributions, we extract the form-factor shapes ${f}_{+}({q}^{2})$ and the total branching fractions $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu})=(1.45\ifmmode\pm\else\textpm\fi{}{0.04}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.06}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ (combined ${\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\ensuremath{\pi}}^{0}$ decay channels assuming isospin symmetry), $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}\ensuremath{\omega}{\ensuremath{\ell}}^{+}\ensuremath{\nu})=(1.19\ifmmode\pm\else\textpm\fi{}{0.16}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.09}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}\ensuremath{\eta}{\ensuremath{\ell}}^{+}\ensuremath{\nu})=(0.38\ifmmode\pm\else\textpm\fi{}{0.05}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.05}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. We also measure $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{\ensuremath{\ell}}^{+}\ensuremath{\nu})=(0.24\ifmmode\pm\else\textpm\fi{}{0.08}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.03}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. We obtain values for the magnitude of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $|{V}_{ub}|$ by direct comparison with three different QCD calculations in restricted ${q}^{2}$ ranges of $B\ensuremath{\rightarrow}\ensuremath{\pi}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$ decays. From a simultaneous fit to the experimental data over the full ${q}^{2}$ range and the FNAL/MILC lattice QCD predictions, we obtain $|{V}_{ub}|=(3.25\ifmmode\pm\else\textpm\fi{}0.31)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, where the error is the combined experimental and theoretical uncertainty.
DOI: 10.1103/physrevd.85.112010
2012
Cited 89 times
Study of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>violation in Dalitz-plot analyses of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo mathvariant="bold">+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><mml:msubsup><mml:mi>K</mml:mi><…
We perform amplitude analyses of the decays $B^0 \to K^+K^-K^0_S$, $B^+ \rightarrow K^+K^-K^+$, and $B^+ \to K^0_S K^0_S K^+$, and measure CP-violating parameters and partial branching fractions. The results are based on a data sample of approximately $470\times 10^6$ $B\bar{B}$ decays, collected with the BABAR detector at the PEP-II asymmetric-energy $B$ factory at the SLAC National Accelerator Laboratory. For $B^+ \to K^+K^-K^+$, we find a direct CP asymmetry in $B^+ \to \phi(1020)K^+$ of $A_{CP}= (12.8\pm 4.4 \pm 1.3)%$, which differs from zero by $2.8 \sigma$. For $B^0 \to K^+K^-K^0_S$, we measure the CP-violating phase $\beta_{\rm eff} (\phi(1020)K^0_S) = (21\pm 6 \pm 2)^\circ$. For $B^+ \to K^0_S K^0_S K^+$, we measure an overall direct CP asymmetry of $A_{CP} = (4 ^{+4}_{-5} \pm 2)%$. We also perform an angular-moment analysis of the three channels, and determine that the $f_X(1500)$ state can be described well by the sum of the resonances $f_0(1500)$, $f_2^{\prime}(1525)$, and $f_0(1710)$.
DOI: 10.1103/physrevd.88.031102
2013
Cited 85 times
Evidence of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo mathvariant="bold">+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>τ</mml:mi><mml:mo mathvariant="bold">+</mml:mo></mml:msup><mml:mi>ν</mml:mi></mml:math>decays with hadronic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>tags
We present a search for the decay ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}\ensuremath{\nu}$ using $467.8\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the BABAR detector at the SLAC PEP-II $B$-Factory. We select a sample of events with one completely reconstructed ${B}^{\ensuremath{-}}$ in the hadronic decay mode (${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{(*)0}{X}^{\ensuremath{-}}$ and ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{X}^{\ensuremath{-}}$). We examine the rest of the event to search for a ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}\ensuremath{\nu}$ decay. We identify the ${\ensuremath{\tau}}^{+}$ lepton in the following modes: ${\ensuremath{\tau}}^{+}\ensuremath{\rightarrow}{e}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$, ${\ensuremath{\tau}}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$, ${\ensuremath{\tau}}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\overline{\ensuremath{\nu}}$ and ${\ensuremath{\tau}}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{+}\overline{\ensuremath{\nu}}$. We find an excess of events with respect to the expected background, which excludes the null signal hypothesis at the level of $3.8\ensuremath{\sigma}$ (including systematic uncertainties) and corresponds to a branching fraction value of $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}\ensuremath{\nu})=({1.83}_{\ensuremath{-}0.49}^{+0.53}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.24(\mathrm{syst}))\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$.
DOI: 10.1103/physrevd.86.072002
2012
Cited 70 times
Study of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>X</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>3915</mml:mn><mml:mo stretchy="false">)</mml:mo><mml:mo>→</mml:mo><mml:mi>J</mml:mi><mml:mo>/</mml:mo><mml:mi>ψ</mml:mi><mml:mi>ω</mml:mi></mml:math>in two-photon collisions
We study the process $\gamma \gamma \to J/\psi \omega$ using a data sample of 519.2 $fb^{-1}$ recorded by the BaBar detector at SLAC at the PEP-II asymmetric-energy $e^+ e^-$ collider at center-of-mass energies near the $\Upsilon(nS)$ ($n = 2,3,4$) resonances. We confirm the existence of the charmonium-like resonance X(3915) decaying to $J/\psi \omega$ with a significance of 7.6 standard deviations, including systematic uncertainties, and measure its mass $(3919.4 \pm 2.2 \pm 1.6) MeV/c^2$ and width $(13 \pm 6 \pm 3) MeV$, where the first uncertainty is statistical and the second systematic. A spin-parity analysis supports the assignment $J^P=0^+$ and therefore the identification of the signal as due to the $\chi_{c0}(2P)$ resonance. In this hypothesis we determine the product between the two-photon width and the final state branching fraction to be $(52 \pm 10 \pm 3) eV$
DOI: 10.1103/physrevlett.109.191801
2012
Cited 69 times
Precision Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mi>s</mml:mi></mml:msub><mml:mi>γ</mml:mi></mml:math>Photon Energy Spectrum, Branching Fraction, and Direct<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>Asymmetry<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi…
The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B → X(s)γ plus B → X(d)γ, is studied using a data sample of (382.8 ± 4.2) × 10(6)Υ(4S) → BB decays collected by the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B → X(s)γ) = (3.21 ± 0.33) × 10(-4) for E(γ) >1.8 GeV and the direct CP asymmetry A(CP) (B → X(s+d)γ) = 0.057 ± 0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.
DOI: 10.1103/physrevd.86.012008
2012
Cited 67 times
Cross sections for the reactions<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo mathvariant="bold">+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo mathvariant="bold">+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo mathvariant="bold">+</mml:mo></mml:…
Cross sections for the reactions e(+)e(-) -> K+K-pi(+)pi(-), K+K-pi(0)pi(0), and
DOI: 10.1103/physrevd.86.052012
2012
Cited 61 times
Exclusive measurements of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>b</mml:mi><mml:mo>→</mml:mo><mml:mi>s</mml:mi><mml:mi>γ</mml:mi></mml:math>transition rate and photon energy spectrum
We use 429 fb$^{-1}$ of $e^+e^-$ collision data collected at the $\Upsilon(4S)$ resonance with the BABAR detector to measure the radiative transition rate of $b\rightarrow s\gamma$ with a sum of 38 exclusive final states. The inclusive branching fraction with a minimum photon energy of 1.9 GeV is found to be $\mathcal{B}(\bar B \rightarrow X_{s}\gamma)=(3.29\pm 0.19\pm 0.48)\times 10^{-4}$ where the first uncertainty is statistical and the second is systematic. We also measure the first and second moments of the photon energy spectrum and extract the best fit values for the heavy-quark parameters, $m_{b}$ and $\mu_{\pi}^{2}$, in the kinetic and shape function models.
DOI: 10.1103/physrevlett.107.021804
2011
Cited 57 times
Search for Production of Invisible Final States in Single-Photon Decays of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">Υ</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>1</mml:mn><mml:mi>S</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math>
We search for single-photon decays of the Υ(1S) resonance, Υ → γ + invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A⁰, or a pair of dark matter particles, χχ. Both A⁰ and χ are assumed to have zero spin. We tag Υ(1S) decays with a dipion transition Υ(2S) → π⁺π⁻Υ(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m(A⁰) ≤ 9.2 GeV and m(χ) ≤ 4.5 GeV in the sample of 98 × 10⁶ Υ(2S) decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states.
DOI: 10.1103/physrevd.89.092002
2014
Cited 46 times
Cross sections for the reactions<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msubsup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mi>S</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msubsup><mml:…
We study the processes $e^+ e^-\to K_S^0 K_L^0 \gamma$, $K_S^0 K_L^0 \pi^+\pi^-\gamma$, $K_S^0 K_S^0 \pi^+\pi^-\gamma$, and $K_S^0 K_S^0 K^+K^-\gamma$, where the photon is radiated from the initial state, providing cross section measurements for the hadronic states over a continuum of center-of-mass energies. The results are based on 469 fb$^{-1}$ of data collected with the BaBar detector at SLAC. We observe the $\phi(1020)$ resonance in the $K_S^0 K_L^0$ final state and measure the product of its electronic width and branching fraction with about 3% uncertainty. We present a measurement of the $e^+ e^-\to K_S^0 K_L^0 $ cross section in the energy range from 1.06 to 2.2 GeV and observe the production of a resonance at 1.67 GeV. We present the first measurements of the $e^+ e^-\to K_S^0 K_L^0 \pi^+\pi^-$, $K_S^0 K_S^0 \pi^+\pi^-$, and $K_S^0 K_S^0 K^+K^-$ cross sections, and study the intermediate resonance structures. We obtain the first observations of \jpsi decay to the $K_S^0 K_L^0 \pi^+\pi^-$, $K_S^0 K_S^0 \pi^+\pi^-$, and $K_S^0 K_S^0 K^+K^-$ final states.
DOI: 10.1103/physrevd.91.012003
2015
Cited 44 times
Study of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>B</mml:mi></mml:mrow><mml:mrow><mml:mo>±</mml:mo><mml:mo>,</mml:mo><mml:mn>0</mml:mn></mml:mrow></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:mi>J</mml:mi><mml:mo stretchy="false">/</mml:mo><mml:mi>ψ</mml:mi><mml:msup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mo…
We study the rare B meson decays B{+-,0} --> J/\psi\ K^+ K^- K{+-,0}, B{+-,0} --> J/\psi\ \phi\ K{+-,0}, and search for B0 --> J/\psi\ \phi, using 469 million BBbar events collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II e+e- asymmetric-energy collider. We present new measurements of branching fractions and a study of the J/\psi\phi mass distribution in search of new charmonium-like states. In addition, we search for the decay B0 --> J/\psi\ \phi, and find no evidence of a signal.
DOI: 10.1103/physrevlett.118.031802
2017
Cited 43 times
Search for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>τ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>τ</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> at the <i>BaBar</i> Experiment
We search for the rare flavor-changing neutral current process $B^{+}\rightarrow K^{+}τ^{+}τ^{-}$ using data from the BABAR experiment. The data sample, collected at the center-of-mass energy of the $Υ{(4S)}$ resonance, corresponds to a total integrated luminosity of 424 fb$^{-1}$ and to 471 million $B\overline{B}$ pairs. We reconstruct one $B$ meson, produced in the $Υ{(4S)}\rightarrow B^{+} B^{-}$ decay, in one of many hadronic decay modes and search for activity compatible with a $B^{+}\rightarrow K^{+} τ^{+}τ^{-}$ decay in the rest of the event. Each $τ$ lepton is required to decay leptonically into an electron or muon and neutrinos. Comparing the expected number of background events with the data sample after applying the selection criteria, we do not find evidence for a signal. The measured branching fraction is ($1.31^{+0.66}_{-0.61}$( stat.)$^{+0.35}_{-0.25}$( sys.)$) \times 10^{-3}$ with an upper limit, at the 90\% confidence level, of $\mathcal{B}(B^{+}\rightarrow K^{+}τ^{+}τ^{-})$$&lt; 2.25\times 10^{-3}$.
DOI: 10.1103/physrevd.84.072006
2011
Cited 51 times
Searches for rare or forbidden semileptonic charm decays
We present searches for rare or forbidden charm decays of the form $X_c^+\to h^\pm\ell^\mp\ell^{(\prime)+}$, where $X_c^+$ is a charm hadron ($D^+$, $D^+_s$, or $\Lambda_c^+$), $h^\pm$ is a pion, kaon, or proton, and $\ell^{(\prime)\pm}$ is an electron or muon. The analysis is based on $384 fb^{-1}$ of $e^+e^-$ annihilation data collected at or close to the $\Upsilon(4S)$ resonance with the BaBar detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the 35 decay modes that are investigated. We establish 90% confidence-level upper limits on the branching fractions between $1 \times 10^{-6}$ and $44 \times 10^{-6}$ depending on the channel. In most cases, these results represent either the first limits or significant improvements on existing limits for the decay modes studied.
DOI: 10.1103/physrevd.85.052003
2012
Cited 49 times
Search for the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>Z</mml:mi><mml:mn>1</mml:mn></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>4050</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo>+</mml:mo></mml:msup></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>Z</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>4250</mml:mn><mml:msup><mml:mo …
We search for the $Z_1(4050)^+$ and $Z_2(4250)^+$ states, reported by the Belle Collaboration, decaying to $\chi_{c1} \pi^+$ in the decays $\bar B^0 \to \chi_{c1} K^- \pi^+$ and $B^+ \to \chi_{c1} K^0_S \pi^+$ where $\chi_{c1} \to \jpsi \gamma$. The data were collected with the BaBar detector at the SLAC PEP-II asymmetric-energy $e^+e^-$ collider operating at center-of-mass energy 10.58 GeV, and correspond to an integrated luminosity of 429 fb$^{-1}$. In this analysis, we model the background-subtracted, efficiency-corrected $\chi_{c1}\pi$ mass distribution using the $K \pi$ mass distribution and the corresponding normalized $K \pi$ Legendre polynomial moments, and then test the need for the inclusion of resonant structures in the description of the $\chi_{c1}\pi$ mass distribution. No evidence is found for the $Z_1(4050)^+$ and $Z_2(4250)^+$ resonances, and 90% confidence level upper limits on the branching fractions are reported for the corresponding $B$-meson decay modes.
DOI: 10.1103/physrevd.91.052022
2015
Cited 34 times
Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msub><mml:mi>ν</mml:mi><mml:mi>e</mml:mi></mml:msub></mml:math>differential decay branching fraction as a function of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:…
Based on a sample of 500 million ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}c\overline{c}$ events recorded by the BABAR detector at c.m. energies of close to 10.6 GeV, we report on a study of the decay ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$. We measure the ratio of branching fractions, ${R}_{D}=\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e})/\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})=0.0713\ifmmode\pm\else\textpm\fi{}0.001{7}_{\text{stat}}\ifmmode\pm\else\textpm\fi{}0.002{4}_{\text{syst}}$, and use the present world average for $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})$ to obtain $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e})=(2.770\ifmmode\pm\else\textpm\fi{}0.06{8}_{\text{stat}}\ifmmode\pm\else\textpm\fi{}0.09{2}_{\text{syst}}\ifmmode\pm\else\textpm\fi{}0.03{7}_{\text{ext}})\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}3}$ where the third error accounts for the uncertainty on the branching fraction for the reference channel. The measured dependence of the differential branching fraction on ${q}^{2}$, the four-momentum transfer squared between the $D$ and the $\ensuremath{\pi}$ meson, is compared to various theoretical predictions for the hadronic form factor, ${f}_{+,D}^{\ensuremath{\pi}}({q}^{2})$, and the normalization $|{V}_{cd}|\ifmmode\times\else\texttimes\fi{}{f}_{+,D}^{\ensuremath{\pi}}({q}^{2}=0)=0.1374\ifmmode\pm\else\textpm\fi{}\phantom{\rule{0ex}{0ex}}0.003{8}_{\text{stat}}\ifmmode\pm\else\textpm\fi{}0.002{2}_{\text{syst}}\ifmmode\pm\else\textpm\fi{}0.000{9}_{\text{ext}}$. is extracted from a fit to data. Using the most recent LQCD prediction of ${f}_{+,D}^{\ensuremath{\pi}}({q}^{2}=0)=0.666\ifmmode\pm\else\textpm\fi{}0.029$, we obtain $|{V}_{cd}|=0.206\ifmmode\pm\else\textpm\fi{}0.00{7}_{\text{exp}}\ifmmode\pm\else\textpm\fi{}0.00{9}_{\mathrm{LQCD}}$. Assuming, instead, $|{V}_{cd}|=|{V}_{us}|=0.2252\ifmmode\pm\else\textpm\fi{}0.0009$, we obtain ${f}_{+,D}^{\ensuremath{\pi}}({q}^{2}=0)=0.610\ifmmode\pm\else\textpm\fi{}0.02{0}_{\text{exp}}\ifmmode\pm\else\textpm\fi{}0.00{5}_{\text{ext}}$. The ${q}^{2}$ dependence of ${f}_{+,D}^{\ensuremath{\pi}}({q}^{2})$ is compared to a variety of multipole parametrizations. This information is applied to ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$ decays and, combined with an earlier ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$ measurement by BABAR, is used to derive estimates of $|{V}_{ub}|$.
DOI: 10.1103/physrevd.104.072002
2021
Cited 21 times
Light meson spectroscopy from Dalitz plot analyses of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>η</mml:mi><mml:mi>c</mml:mi></mml:msub></mml:math> decays to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mrow><mml:mi>η</mml:mi></mml:mrow><mml:mrow><mml:mo>′</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup></mml…
We study the processes $\gamma \gamma \to \eta_c \to \eta' K^+ K^-$, $\eta' \pi^+ \pi^-$, and $\eta \pi^+ \pi^-$ using a data sample of 519 $fb^{-1}$ recorded with the BaBar detector operating at the SLAC PEP-II asymmetric-energy $e^+e^-$ collider at center-of-mass energies at and near the $\Upsilon(nS)$ ($n = 2,3,4$) resonances. This is the first observation of the decay $\eta_c \to \eta' K^+ K^-$ and we measure the branching fraction $\Gamma(\eta_c \to \eta' K^+ K^-)/(\Gamma(\eta_c \to \eta' \pi^+ \pi^-)=0.644\pm 0.039_{\rm stat}\pm 0.032_{\rm sys}$. Significant interference is observed between $\gamma \gamma \to \eta_c\to \eta \pi^+ \pi^-$ and the non-resonant two-photon process $\gamma \gamma \to \eta \pi^+ \pi^-$. A Dalitz plot analysis is performed of $\eta_c$ decays to $\eta' K^+ K^-$, $\eta' \pi^+ \pi^-$, and $\eta \pi^+ \pi^-$. Combined with our previous analysis of $\eta_c \to K \bar K \pi$, we measure the $K^*_0(1430)$ parameters and the ratio between its $\eta' K$ and $\pi K$ couplings. The decay $\eta_c \to \eta' \pi^+ \pi^-$ is dominated by the $f_0(2100)$ resonance, also observed in $J/\psi$ radiative decays. A new $a_0(1700) \to \eta \pi$ resonance is observed in the $\eta_c \to \eta \pi^+ \pi^-$ channel. We also compare $\eta_c$ decays to $\eta$ and $\eta'$ final states in association with scalar mesons as they relate to the identification of the scalar glueball.
DOI: 10.1103/physrevd.80.071103
2009
Cited 44 times
Measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mtext mathvariant="normal">−</mml:mtext><mml:msup><mml:mover accent="true"><mml:mi>D</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mn>0</mml:mn></mml:msup></mml:math>mixing using the ratio of lifetimes for the decays<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:…
We measure the rate of D0−¯¯¯D0 mixing with the observable yCP=(τKπ/τKK)−1, where τKK and τKπ are, respectively, the mean lifetimes of CP-even D0→K+K− and CP-mixed D0→K−π+ decays, using a data sample of 384 fb−1 collected by the BABAR detector at the SLAC PEP-II asymmetric-energy B Factory. From a sample of D0 and ¯¯¯D0 decays where the initial flavor of the decaying meson is not determined, we obtain yCP=[1.12±0.26(stat)±0.22(syst)]%, which excludes the no-mixing hypothesis at 3.3σ, including both statistical and systematic uncertainties. This result is in good agreement with a previous BABAR measurement of yCP obtained from a sample of D*+→D0π+ events, where the D0 decays to K−π+, K+K−, and π+π−, which is disjoint with the untagged D0 events used here. Combining the two results taking into account statistical and systematic uncertainties, where the systematic uncertainties are assumed to be 100% correlated, we find yCP=[1.16±0.22(stat)±0.18(syst)]%, which excludes the no-mixing hypothesis at 4.1σ.Received 7 August 2009DOI:https://doi.org/10.1103/PhysRevD.80.071103©2009 American Physical Society
DOI: 10.1103/physrevd.81.052010
2010
Cited 43 times
Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi><mml:mo>*</mml:mo><mml:mo>→</mml:mo><mml:msub><mml:mi>η</mml:mi><mml:mi>c</mml:mi></mml:msub></mml:math>transition form factor
We study the reaction e+e- --> e+e- eta_c, eta_c --> K_S K+- pi-+ and obtain eta_c mass and width values 2982.2+-0.4+-1.6 MeV/c^2 and 31.7+-1.2+-0.8 MeV, respectively. We find Gamma(eta_c --> gamma gamma)B(eta_c --> K anti-K pi)=0.374+-0.009+-0.031 keV, and measure the gamma gamma* --> eta_c transition form factor in the momentum transfer range from 2 to 50 GeV^2. The analysis is based on 469 fb-1 of integrated luminosity collected at PEP-II with the BABAR detector at e+e- center-of-mass energies near 10.6 GeV.
DOI: 10.1103/physrevd.83.032002
2011
Cited 39 times
Studies of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>η</mml:mi><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msub><mml:mi>ν</mml:mi><mml:mi>τ</mml:mi></mml:msub></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>η</mml:mi><mml:msup><mml:mi>π</mml:mi…
We report on analyses of tau lepton decays $\tau^- \to \eta K^- \nu_{\tau}$ and $\tau^- \to \eta \pi^- \nu_{\tau}$, with $\eta \to \pi^+ \pi^- \pi^0$, using 470 fb$^{-1}$ of data from the Babar experiment at PEP-II, collected at center-of-mass energies at and near the $\Upsilon(4S)$ resonance. We measure the branching fraction for the $\tau^- \to \eta K^- \nu_{\tau}$ decay mode, $\Br(\tau^- \to \eta K^- \nu_{\tau}) = (1.42\pm0.11\text{(stat)}\pm0.07\text{(syst)})\times10^{-4}$, and report a 95% confidence level upper limit for the second-class current process $\tau^- \to \eta \pi^- \nu_{\tau}$, $\Br(\tau^- \to \eta \pi^- \nu_{\tau}) < 9.9\times10^{-5}$.
DOI: 10.1103/physrevd.86.112008
2012
Cited 37 times
Measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="script">B</mml:mi></mml:math>(<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mi>s</mml:mi></mml:msub><mml:mi>γ</mml:mi></mml:math>), the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mi>s</mml:mi></…
The photon spectrum in $B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma}$ decay, where ${X}_{s}$ is any strange hadronic state, is studied using a data sample of $(382.8\ifmmode\pm\else\textpm\fi{}4.2)\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}B\overline{B}$ events collected by the BABAR experiment at the PEP-II collider. The spectrum is used to measure the branching fraction $\mathcal{B}(B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma})=(3.21\ifmmode\pm\else\textpm\fi{}0.15\ifmmode\pm\else\textpm\fi{}0.29\ifmmode\pm\else\textpm\fi{}0.08)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and the first, second, and third moments $⟨{E}_{\ensuremath{\gamma}}⟩=2.267\ifmmode\pm\else\textpm\fi{}0.019\ifmmode\pm\else\textpm\fi{}0.032\ifmmode\pm\else\textpm\fi{}0.003\text{ }\text{ }\mathrm{GeV}$, $⟨({E}_{\ensuremath{\gamma}}\ensuremath{-}⟨{E}_{\ensuremath{\gamma}}⟩{)}^{2}⟩=0.0484\ifmmode\pm\else\textpm\fi{}0.0053\ifmmode\pm\else\textpm\fi{}0.0077\ifmmode\pm\else\textpm\fi{}0.0005\text{ }\text{ }{\mathrm{GeV}}^{2}$, and $⟨({E}_{\ensuremath{\gamma}}\ensuremath{-}⟨{E}_{\ensuremath{\gamma}}⟩{)}^{3}⟩=\ensuremath{-}0.0048\ifmmode\pm\else\textpm\fi{}0.0011\ifmmode\pm\else\textpm\fi{}0.0011\ifmmode\pm\else\textpm\fi{}0.0004\text{ }\text{ }{\mathrm{GeV}}^{3}$, for the range ${E}_{\ensuremath{\gamma}}&gt;1.8\text{ }\text{ }\mathrm{GeV}$, where ${E}_{\ensuremath{\gamma}}$ is the photon energy in the $B$-meson rest frame. Results are also presented for narrower ${E}_{\ensuremath{\gamma}}$ ranges. In addition, the direct $CP$ asymmetry ${A}_{CP}(B\ensuremath{\rightarrow}{X}_{s+d}\ensuremath{\gamma})$ is measured to be $0.057\ifmmode\pm\else\textpm\fi{}0.063$. The spectrum itself is also unfolded to the $B$-meson rest frame; that is the frame in which theoretical predictions for its shape are made.
DOI: 10.1103/physrevd.85.031102
2012
Cited 37 times
Search for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>violation in the decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><mml:msubsup><mml:mi>K</mml:mi><mml:mi>s</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:mo mathvariant="…
We report a search for CP violation in the decay \tau- -> \pi - \K^0_S (>= 0 \pi 0) \nu_\tau\ using a dataset of 437 million \tau\ lepton pairs, corresponding to an integrated luminosity of 476 fb^{-1}, collected with the BABAR detector at the PEP-II asymmetric energy e+e- storage rings. The CP-violating decay-rate asymmetry is determined to be (-0.45 +/- 0.24 +/- 0.11)%, approximately three standard deviations from the Standard Model prediction of (0.33 +/- 0.01)%.
DOI: 10.1103/physrevd.83.052011
2011
Cited 36 times
Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>ℓ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mi>ν</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>η</mml:mi><mml:mrow…
Measurement of the B(0) -> pi(-)l(+)nu and B(+) -> eta(l)l(+)nu branching fractions, the B(0) -> pi(-)l(+)nu and B(+) -> eta l(+
DOI: 10.1103/physrevd.83.112010
2011
Cited 34 times
Amplitude analysis of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>and evidence of direct<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>…
We analyze the decay B0--&gt;K+ pi- pi0 with a sample of 454 million B Bbar events collected by the BaBar detector at the PEP-II asymmetric-energy B factory at SLAC, and extract the complex amplitudes of seven interfering resonances over the Dalitz plot. These results are combined with amplitudes measured in B0--&gt;K_S pi+ pi- decays to construct isospin amplitudes from B0--&gt;K* pi and B0--&gt;rho K decays. We measure the phase of the isospin amplitude Phi_3/2, useful in constraining the CKM unitarity triangle angle gamma and evaluate a CP rate asymmetry sum rule sensitive to the presence of new physics operators. We measure direct CP violation in B0--&gt;K*+ pi- decays at the level of 3 sigma when measurements from both B0--&gt;K+ pi- pi0 and B0--&gt;K_S pi+ pi- decays are combined.
DOI: 10.1103/physrevd.91.052002
2015
Cited 33 times
Dalitz plot analyses of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>D</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml…
We present Dalitz plot analyses for the decays of $B$ mesons to ${D}^{\ensuremath{-}}{D}^{0}{K}^{+}$ and ${\overline{D}}^{0}{D}^{0}{K}^{+}$. We report the observation of the ${D}_{s1}^{*}(2700{)}^{+}$ resonance in these two channels and obtain measurements of the mass $M({D}_{s1}^{*}(2700{)}^{+})={2699}_{\ensuremath{-}7}^{+14}\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and of the width $\mathrm{\ensuremath{\Gamma}}({D}_{s1}^{*}(2700{)}^{+})={127}_{\ensuremath{-}19}^{+24}\text{ }\text{ }\mathrm{MeV}$, including statistical and systematic uncertainties. In addition, we observe an enhancement in the ${D}^{0}{K}^{+}$ invariant mass around $2350--2500\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ in both decays ${B}^{0}\ensuremath{\rightarrow}{D}^{\ensuremath{-}}{D}^{0}{K}^{+}$ and ${B}^{+}\ensuremath{\rightarrow}{\overline{D}}^{0}{D}^{0}{K}^{+}$, which we are not able to interpret. The results are based on $429\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data containing $471\ifmmode\times\else\texttimes\fi{}1{0}^{6}B\overline{B}$ pairs collected at the $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance with the BABAR detector at the SLAC National Accelerator Laboratory.
DOI: 10.1103/physrevlett.114.171801
2015
Cited 32 times
Search for Long-Lived Particles in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>Collisions
We present a search for a neutral, long-lived particle L that is produced in e+ e- collisions and decays at a significant distance from the e+ e- interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an e+ e- data sample with a luminosity of 489.1 fb(-1) collected by the BABAR detector at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and just below the ϒ(4S). Fitting the two-track mass distribution in search of a signal peak, we do not observe a significant signal, and set 90% confidence level upper limits on the product of the L production cross section, branching fraction, and reconstruction efficiency for six possible two-body L decay modes as a function of the L mass. The efficiency is given for each final state as a function of the mass, lifetime, and transverse momentum of the candidate, allowing application of the upper limits to any production model. In addition, upper limits are provided on the branching fraction B(B→XsL), where Xs is a strange hadronic system.
DOI: 10.1097/00000542-199412000-00028
1994
Cited 53 times
Metabolism of Glucose, Glycogen, and High-energy Phosphates during Complete Cerebral Ischemia
Increases in brain glucose will worsen outcome after global cerebral ischemia, and some experimental evidence suggests that the duration of hyperglycemia also may influence outcome. Different types of hyperglycemia were studied to identify metabolic differences that might account for alterations in postischemic outcome.Ninety pentobarbital-anesthetized Sprague-Dawley rats were divided into three groups: normoglycemic nondiabetic rats (N) (n = 30), chronically hyperglycemic diabetic rats (HD) (n = 30), and acutely hyperglycemic, glucose-infused nondiabetic rats (HN) (n = 30). These groups were further subdivided into groups of six rats each that received 0, 2.5, 5, 10, or 15 min of complete cerebral ischemia (potassium chloride--induced cardiac arrest). Brains were excised after 10-kW focused microwave radiation and metabolites were measured using enzymatic fluorometric techniques.At all study intervals, plasma glucose concentrations in HD and HN were fourfold greater than in N. Before ischemia, brain glucose concentrations in all groups were proportional to plasma glucose concentrations; however, brain glycogen concentrations did not differ among groups. After the onset of ischemia, there was an immediate diminution of brain glucose, glycogen, adenosine triphosphate (ATP), and phosphocreatine that in all cases was most pronounced during the initial 2.5 min of ischemia. Consumption of carbohydrate stores and lactate production were greater in HD and HN than in N. HD had lesser preischemic ATP concentrations and energy charges relative to N and HN (P < 0.05), perhaps reflecting their disease state; however, at 2.5 min of ischemia, the relationship of ATP concentrations and energy charges was HN > HD > N (P < 0.05 among all). In all groups, ATP and phosphocreatine were more than 96% depleted by 10 min of ischemia. With few exceptions (ATP concentrations and energy charges before ischemia and at 2.5 min, and lactate concentration in HD < HN at 15 min), there were no measured metabolic differences between HD and HN.In these studies, the duration of hyperglycemia did not affect intraischemic carbohydrate consumption. At short durations of ischemia (2.5 min), both HD and HN groups had greater intraischemic ATP concentrations and energy charges than N; however, at longer durations of ischemia (> 5.0 min), high-energy phosphate depletion was similarly severe in all groups. These studies suggest that energy failure is not the origin of worse postischemic neurologic injury in hyperglycemic subjects, nor does energy failure readily explain reported differences between acutely and chronically hyperglycemic subjects exposed to global cerebral ischemia.
DOI: 10.1103/physrevlett.97.201801
2006
Cited 43 times
Measurements of Branching Fractions, Polarizations, and Direct<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>-Violation Asymmetries in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:mi>ρ</mml:mi><mml:msup><mml:mi>K</mml:mi><mml:mo>*</mml:mo></mml:msup></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi…
We report searches for $B$-meson decays to the charmless final states $\ensuremath{\rho}{K}^{*}$ and ${f}_{0}(980){K}^{*}$ with a sample of $232\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected with the BABAR detector at the PEP-II ${e}^{+}{e}^{\ensuremath{-}}$ collider. We measure in units of ${10}^{\ensuremath{-}6}$ the following branching fractions, where the first error quoted is statistical and the second systematic, or upper limits are given at the 90% confidence level : $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}{K}^{*+})&lt;6.1$, $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{+}{K}^{*0})=9.6\ifmmode\pm\else\textpm\fi{}1.7\ifmmode\pm\else\textpm\fi{}1.5$, $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{\ensuremath{-}}{K}^{*+})&lt;12.0$, $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}{K}^{*0})=5.6\ifmmode\pm\else\textpm\fi{}0.9\ifmmode\pm\else\textpm\fi{}1.3$, $\mathcal{B}\mathbf{(}{B}^{+}\ensuremath{\rightarrow}{f}_{0}(980){K}^{*+}\mathbf{)}=5.2\ifmmode\pm\else\textpm\fi{}1.2\ifmmode\pm\else\textpm\fi{}0.5$, and $\mathcal{B}\mathbf{(}{B}^{0}\ensuremath{\rightarrow}{f}_{0}(980){K}^{*0}\mathbf{)}&lt;4.3$. For the significant modes, we also measure the fraction of longitudinal polarization and the charge asymmetry: ${f}_{L}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{+}{K}^{*0})=0.52\ifmmode\pm\else\textpm\fi{}0.10\ifmmode\pm\else\textpm\fi{}0.04$, ${f}_{L}({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}{K}^{*0})=0.57\ifmmode\pm\else\textpm\fi{}0.09\ifmmode\pm\else\textpm\fi{}0.08$, ${\mathcal{A}}_{CP}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{+}{K}^{*0})=\ensuremath{-}0.01\ifmmode\pm\else\textpm\fi{}0.16\ifmmode\pm\else\textpm\fi{}0.02$, ${\mathcal{A}}_{CP}({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}{K}^{*0})=0.09\ifmmode\pm\else\textpm\fi{}0.19\ifmmode\pm\else\textpm\fi{}0.02$, and ${\mathcal{A}}_{CP}\mathbf{(}{B}^{+}\ensuremath{\rightarrow}{f}_{0}(980){K}^{*+}\mathbf{)}=\ensuremath{-}0.34\ifmmode\pm\else\textpm\fi{}0.21\ifmmode\pm\else\textpm\fi{}0.03$.
DOI: 10.1103/physrevd.82.072004
2010
Cited 35 times
Measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>observables in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msub><mml:mi>D</mml:mi><mml:mrow><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:mrow></mml:msub><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup></mml:math>decays and constraints on the CKM …
Using the entire sample of 467 million Y(4S) --> BBbar decays collected with the BaBar detector at the PEP-II asymmetric-energy B factory at SLAC, we perform a "GLW" analysis of B+- --> D K+- decays, using decay modes in which the neutral D meson decays to either CP-eigenstates or non-CP-eigenstates. We measure the partial decay rate charge asymmetries for CP-even and CP-odd D final states to be A_CP+ = 0.25+-0.06+-0.02 and A_CP- = -0.09+-0.07+-0.02, respectively, where the first error is the statistical and the second is the systematic uncertainty. The parameter A_CP+ is different from zero with a significance of 3.6 standard deviations, constituting evidence for direct CP violation. We also measure the ratios of the charged-averaged B partial decay rates in CP and non-CP decays, R_CP+ = 1.18+-0.09+-0.05 and R_CP- = 1.07+-0.08+-0.04. We infer frequentist confidence intervals for the angle gamma of the (db) unitarity triangle, for the strong phase difference delta_B, and for the amplitude ratio r_B, which are related to the B- --> DK- decay amplitude by r_Be^{i(delta_B-gamma)} = A(B- --> anti-D0 K^-)/A(B- --> D0 K-). Including statistical and systematic uncertainties, we obtain 0.24<r_B<0.45 (0.06<r_B<0.51) and, modulo 180 degrees, 11.3 degrees < gamma < 22.7 degrees or 80.9 degrees < gamma < 99.1 degrees or 157.3 degrees < gamma < 168.7 degrees (7.0 degrees < gamma < 173.0 degrees) at the 68% (95%) confidence level.
DOI: 10.1103/physrevd.81.111103
2010
Cited 35 times
Search for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>violation using<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>T</mml:mi></mml:math>-odd correlations in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml…
We search for CP violation in a sample of 4.7×104 Cabibbo suppressed D0→K+K−π+π− decays. We use 470 fb−1 of data recorded by the BABAR detector at the PEP-II asymmetric-energy e+e− storage rings running at center-of-mass energies near 10.6 GeV. CP violation is searched for in the difference between the T-odd asymmetries, obtained using triple product correlations, measured for D0 and ¯¯¯D0 decays. The measured CP violation parameter is AT=(1.0±5.1stat±4.4syst)×10−3.Received 17 March 2010DOI:https://doi.org/10.1103/PhysRevD.81.111103©2010 American Physical Society
DOI: 10.1103/physrevd.82.091103
2010
Cited 32 times
Measurement of the absolute branching fractions for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mo>−</mml:mo></mml:msubsup><mml:mo>→</mml:mo><mml:msup><mml:mi>ℓ</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msub><mml:mover accent="true"><mml:mi>ν</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mi>ℓ</mml:mi></mml:msub></mml:math>and extraction of the decay constant<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" …
The absolute branching fractions for the decays $D^-_s\!\rightarrow\!\ell^-\bar{\nu}_{\ell}$ ($\ell=e$, $\mu$, or $\tau$) are measured using a data sample corresponding to an integrated luminosity of 521 fb$^{-1}$ collected at center of mass energies near 10.58 GeV with the \mbox{\slshape B\kern-0.1em{\smaller A}\kern-0.1em B\kern-0.1em{\smaller A\kern-0.2em R}} detector at the PEP-II $e^+e^-$ collider at SLAC. The number of $D^-_s$ mesons is determined by reconstructing the recoiling system $DKX\gamma$ in events of the type $e^+e^-{\rightarrow}DKXD^{*-}_s$, where $D^{*-}_s\rightarrow D^-_s\gamma$ and $X$ represents additional pions from fragmentation. The $D^-_s\!\rightarrow\!\ell^-\bar{\nu}_{\ell}$ events are detected by full or partial reconstruction of the recoiling system $DKX\gamma\ell$. The branching fraction measurements are combined to determine the $D^-_s$ decay constant $f_{D_s} = (258.6 \pm 6.4 \pm 7.5)$ MeV, where the first uncertainty is statistical and the second is systematic.
DOI: 10.1103/physrevd.86.032004
2012
Cited 32 times
Study of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mover accent="true"><mml:mi>B</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mo>→</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mi>u</mml:mi></mml:msub><mml:mi>ℓ</mml:mi><mml:mover accent="true"><mml:mi>ν</mml:mi><mml:mo>¯</mml:mo></mml:mover></mml:math>decays in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mover accent="true"><mml:mi>B</mml:mi><mml:mo>¯</mml:mo></mml…
We report measurements of partial branching fractions for inclusive charmless semileptonic B decays Bbar --> Xu l nubar, and the determination of the CKM matrix element |V_{ub}|. The analysis is based on a sample of 467 million Upsilon(4S) --> BBar decays recorded with the BaBar detector at the PEP-II e^+ e^- storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions DeltaB in several restricted regions of phase space and determine the CKM element |V_{ub}| based on four different QCD predictions. For decays with a charged lepton momentum p_l^* > 1.0 GeV in the B meson rest frame, we obtain DeltaB = (1.80 \pm 0.13 (stat.) \pm 0.15 (sys.) \pm 0.02 (theo.)) \times 10^{-3} from a fit to the two-dimensional mX-q^2 distribution. Here, mX refers to the invariant mass of the final state hadron X and q^2 is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract |V_{ub}| = (4.33\pm 0.24 (exp.) \pm 0.15 (theo.)) \times 10^{-3} as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for B^0 and B^- decays and derive a limit on the isospin breaking in Bbar --> Xu l nubar decays.
DOI: 10.1103/physrevlett.111.111801
2013
Cited 30 times
Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mo>*</mml:mo></mml:msup><mml:mo stretchy="false">(</mml:mo><mml:mn>2010</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo mathvariant="bold">+</mml:mo></mml:msup></mml:math>Meson Width and the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mo>*</mml:mo></mml:msup><mml:mo stretchy="false">(</mml:mo><mml:…
We measure the mass difference $\ensuremath{\Delta}{m}_{0}$ between the ${D}^{*}(2010{)}^{+}$ and the ${D}^{0}$ and the natural linewidth $\ensuremath{\Gamma}$ of the transition ${D}^{*}(2010{)}^{+}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{+}$. The data were recorded with the BABAR detector at center-of-mass energies at and near the $\ensuremath{\Upsilon}(4S)$ resonance, and correspond to an integrated luminosity of approximately $477\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. The ${D}^{0}$ is reconstructed in the decay modes ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ and ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$. For the decay mode ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ we obtain $\ensuremath{\Gamma}=(83.4\ifmmode\pm\else\textpm\fi{}1.7\ifmmode\pm\else\textpm\fi{}1.5)\text{ }\text{ }\mathrm{keV}$ and $\ensuremath{\Delta}{m}_{0}=(145425.6\ifmmode\pm\else\textpm\fi{}0.6\ifmmode\pm\else\textpm\fi{}1.8)\text{ }\text{ }\mathrm{keV}$, where the quoted errors are statistical and systematic, respectively. For the ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ mode we obtain $\ensuremath{\Gamma}=(83.2\ifmmode\pm\else\textpm\fi{}1.5\ifmmode\pm\else\textpm\fi{}2.6)\text{ }\text{ }\mathrm{keV}$ and $\ensuremath{\Delta}{m}_{0}=(145426.6\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}2.0)\text{ }\text{ }\mathrm{keV}$. The combined measurements yield $\ensuremath{\Gamma}=(83.3\ifmmode\pm\else\textpm\fi{}1.2\ifmmode\pm\else\textpm\fi{}1.4)\text{ }\text{ }\mathrm{keV}$ and $\ensuremath{\Delta}{m}_{0}=(145425.9\ifmmode\pm\else\textpm\fi{}0.4\ifmmode\pm\else\textpm\fi{}1.7)\text{ }\text{ }\mathrm{keV}$; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.
DOI: 10.1103/physrevd.85.091107
2012
Cited 30 times
Search for the decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi></mml:math>and measurement of the branching fraction for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>π</mml:mi><mml…
We search for the rare decay of the ${D}^{0}$ meson to two photons, ${D}^{0}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$, and present a measurement of the branching fraction for a ${D}^{0}$ meson decaying to two neutral pions, $B({D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0})$. The data sample analyzed corresponds to an integrated luminosity of $470.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected by the BABAR detector at the PEP-II asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider at SLAC. We place an upper limit on the branching fraction, $B({D}^{0}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})&lt;2.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, at 90% confidence level. This limit improves on the existing limit by an order of magnitude. We also find $B({D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0})=(8.4\ifmmode\pm\else\textpm\fi{}0.1\ifmmode\pm\else\textpm\fi{}0.4\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$.
DOI: 10.1103/physrevd.85.071103
2012
Cited 29 times
Search for lepton-number violating processes in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>h</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>l</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>l</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math>decays
We have searched for the lepton-number violating processes ${B}^{+}\ensuremath{\rightarrow}{h}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{+}$ with ${h}^{\ensuremath{-}}={K}^{\ensuremath{-}}/{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\ensuremath{\ell}}^{+}={e}^{+}/{\ensuremath{\mu}}^{+}$, using a sample of $471\ifmmode\pm\else\textpm\fi{}3$ million $B\overline{B}$ events collected with the BABAR detector at the PEP-II ${e}^{+}{e}^{\ensuremath{-}}$ collider at the SLAC National Accelerator Laboratory. We find no evidence for these decays and place 90%-confidence-level upper limits on their branching fractions $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{e}^{+})&lt;2.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$, $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{e}^{+}{e}^{+})&lt;3.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$, $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{+})&lt;10.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$, and $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{+})&lt;6.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$.
DOI: 10.1103/physrevlett.111.101802
2013
Cited 28 times
Search for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>Violation in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mover accent="true"><mml:mi>B</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mn>0</mml:mn></mml:msup></mml:math>Mixing Using …
We present results of a search for $CP$ violation in ${B}^{0}\mathrm{\text{\ensuremath{-}}}\text{ }{\overline{B}}^{0}$ mixing with the BABAR detector. We select a sample of ${B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}X{\ensuremath{\ell}}^{+}\ensuremath{\nu}$ decays with a partial reconstruction method and use kaon tagging to assess the flavor of the other $B$ meson in the event. We determine the $CP$ violating asymmetry ${\mathcal{A}}_{CP}\ensuremath{\equiv}[N({B}^{0}{B}^{0})\ensuremath{-}N({\overline{B}}^{0}{\overline{B}}^{0})]/[N({B}^{0}{B}^{0})+N({\overline{B}}^{0}{\overline{B}}^{0})]=(0.06\ifmmode\pm\else\textpm\fi{}{0.17}_{\ensuremath{-}0.32}^{+0.38})%$, corresponding to ${\ensuremath{\Delta}}_{CP}=1\ensuremath{-}|q/p|=(0.29\ifmmode\pm\else\textpm\fi{}{0.84}_{\ensuremath{-}1.61}^{+1.88})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$.
DOI: 10.1103/physrevd.85.112009
2012
Cited 28 times
Initial-state radiation measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>cross section
We study the process e+e- -> pi+pi-pi+pi-gamma, with a photon emitted from the initial-state electron or positron, using 454.3 fb^-1 of data collected with the BABAR detector at SLAC, corresponding to approximately 260,000 signal events. We use these data to extract the non-radiative sigma(e+e- ->pi+pi-pi+pi-) cross section in the energy range from 0.6 to 4.5 Gev. The total uncertainty of the cross section measurement in the peak region is less than 3%, higher in precision than the corresponding results obtained from energy scan data.
DOI: 10.1103/physrevd.92.111101
2015
Cited 25 times
Collins asymmetries in inclusive charged<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>K</mml:mi><mml:mi>K</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>K</mml:mi><mml:mi>π</mml:mi></mml:mrow></mml:math>pairs produced in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></…
We present measurements of Collins asymmetries in the inclusive process $e^+e^- \rightarrow h_1 h_2 X$, $h_1h_2=KK,\, K\pi,\, \pi\pi$, at the center-of-mass energy of 10.6 GeV, using a data sample of 468 fb$^{-1}$ collected by the BaBar experiment at the PEP-II $B$ factory at SLAC National Accelerator Center. Considering hadrons in opposite thrust hemispheres of hadronic events, we observe clear azimuthal asymmetries in the ratio of unlike- to like-sign, and unlike- to all charged $h_1 h_2$ pairs, which increase with hadron energies. The $K\pi$ asymmetries are similar to those measured for the $\pi\pi$ pairs, whereas those measured for high-energy $KK$ pairs are, in general, larger.
DOI: 10.1103/physrevlett.125.181801
2020
Cited 20 times
Search for a Dark Leptophilic Scalar in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> Collisions
Many scenarios of physics beyond the Standard Model predict the existence of new gauge singlets, which might be substantially lighter than the weak scale. The experimental constraints on additional scalars with masses in the MeV to GeV range could be significantly weakened if they interact predominantly with leptons rather than quarks. At an $e^+e^-$ collider, such a leptophilic scalar ($\phi_L$) would be produced predominantly through radiation from a $\tau$ lepton. We report herein a search for $e^+e^- \to \tau^+\tau^- \phi_L$, $\phi_L \to \ell^+\ell^-$ ($\ell=e,\mu$) using data collected by the BABAR experiment at SLAC. No significant signal is observed, and we set limits on the $\phi_L$ coupling to leptons in the range 0.04 < m$_{\phi_L}$ < 7.0 GeV. These bounds significantly improve upon the current constraints, excluding almost entirely the parameter space favored by the observed discrepancy in the muon anomalous magnetic moment below 4 GeV at 90\% confidence level.
DOI: 10.1103/physrevd.107.092001
2023
Cited 3 times
Search for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math> mesogenesis at <i>BaBar</i>
A new mechanism has been proposed to simultaneously explain the presence of dark matter and the matter-antimatter asymmetry in the universe. This scenario predicts exotic $B$ meson decays into a baryon and a dark sector anti-baryon ($\psi_D$) with branching fractions accessible at $B$ factories. We present a search for $B \rightarrow \Lambda \psi_D$ decays using data collected by the $BABAR$ experiment at SLAC. This reaction is identified by fully reconstructing the accompanying $B$ meson and requiring the presence of a single $\Lambda$ baryon in the remaining particles. No significant signal is observed, and bounds on the $B \rightarrow \Lambda \psi_D$ branching fraction are derived in the range $0.13 - 5.2\times 10^{-5}$ for $1.0 < m_{\psi_D} < 4.2$ GeV/$c^{2}$. These results set strong constraints on the parameter space allowed by the theory.
2006
Cited 37 times
The unexpected benefits of Sarbanes-Oxley.
In the wake of a series of gross corporate abuses around the turn of the century, Congress passed Sarbanes-Oxley, which was intended to make corporate governance more rigorous, financial practices more transparent, and management criminally liable for lapses. The first year of implementation was costly and onerous, far more so than companies had been led to expect. In the view of a few open-minded firms, however, the second year of compliance turned out to be not only less costly and less onerous (as doing something for the second time usually turns out to be), but a source of valuable insights into operations, which management has translated into improved efficiencies and cost savings. The areas of improvement go well beyond technical statutory compliance. They include a strengthened control environment; more reliable documentation; increased audit committee involvement; better, less burdensome compliance with other statutory regimes; more standardized processes for IT and other functions; reduced complexity oforganizational processes; better internal controls within partner companies; and more effective use of both automated and manual controls. The result is not only shareholder protection, the official purpose of the act, but also enhanced shareholder value. More than a year since the first deadline arrived, Sarbanes-Oxley still inspires fear--of enforcement actions, of the stock market's reaction to a deficiency, and of personal liability. Fear can be a powerful generator of upstanding conduct. But businesses run on discovering and creating value. Companies need to start viewing Sarbanes-Oxley as an ally in that effort.
DOI: 10.1103/physrevd.80.092005
2009
Cited 32 times
Measurements of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>τ</mml:mi></mml:math>mass and the mass difference of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>at<i>BABAR</i>
We present the result from a precision measurement of the mass of the $\tau$ lepton, $M_\tau$, based on $423 fb^{-1}$ of data recorded at the $\Upsilon(4S)$ resonance with the BaBar detector. Using a pseudomass endpoint method, we determine the mass to be $1776.68 \pm 0.12 (stat) \pm 0.41 (syst) MeV$. We also measure the mass difference between the $\tau^+$ and $\tau^-$, and obtain $(M_{\tau^{+}}-M_{\tau^{-}})/M^\tau_{AVG} = (-3.4 \pm 1.3 (stat) \pm 0.3 (syst)) \times 10^{-4}$, where $M^\tau_{AVG}$ is the average value of $M_{\tau^+}$ and $M_{\tau^-}$.
DOI: 10.1103/physrevlett.103.211802
2009
Cited 31 times
Measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>*</mml:mo></mml:msup><mml:mo stretchy="false">(</mml:mo><mml:mn>892</mml:mn><mml:mo stretchy="false">)</mml:mo><mml:mi>γ</mml:mi></mml:math>Branching Fractions and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>and Isospin Asymmetries
We present an analysis of the decays ${B}^{0}\ensuremath{\rightarrow}{K}^{*0}(892)\ensuremath{\gamma}$ and ${B}^{+}\ensuremath{\rightarrow}{K}^{*+}(892)\ensuremath{\gamma}$ using a sample of about $383\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ events collected with the BABAR detector at the PEP-II asymmetric energy $B$ factory. We measure the branching fractions $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{K}^{*0}\ensuremath{\gamma})=(4.47\ifmmode\pm\else\textpm\fi{}0.10\ifmmode\pm\else\textpm\fi{}0.16)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ and $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{K}^{*+}\ensuremath{\gamma})=(4.22\ifmmode\pm\else\textpm\fi{}0.14\ifmmode\pm\else\textpm\fi{}0.16)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. We constrain the direct $CP$ asymmetry to be $\ensuremath{-}0.033&lt;\mathcal{A}(B\ensuremath{\rightarrow}{K}^{*}\ensuremath{\gamma})&lt;0.028$ and the isospin asymmetry to be $0.017&lt;{\ensuremath{\Delta}}_{0\ensuremath{-}}&lt;0.116$, where the limits are determined by the 90% confidence interval and include both the statistical and systematic uncertainties.
DOI: 10.1103/physrevd.82.052004
2010
Cited 31 times
Exclusive production of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mo>+</mml:mo></mml:msubsup><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mo>−</mml:mo></mml:msubsup></mml:math>,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mrow><mml:mo>*</mml:mo><mml:mo>+</mml:mo></mml:mrow></mml:msubsup><mml:msubsup><mml:mi>D</mml:mi><…
We perform a study of exclusive production of$D^+_sD^-_s$, $D^{*+}_sD^-_s$, and $D^{*+}_sD^{*-}_s$ final states in initial-state-radiation events from $e^+ e^-$ annihilations at a center-of-mass energy near 10.58 GeV, to search for charmonium $1^{--}$ states. The data sample corresponds to an integrated luminosity of 525 $fb^{-1}$ and was recorded by the BaBar experiment at the PEP-II storage ring. The $D^+_sD^-_s$, $D^{*+}_sD^-_s$, and $D^{*+}_sD^{*-}_s$ mass spectra show evidence of the known $\psi$ resonances. Limits are extracted for the branching ratios of the decays $X(4260)\to D^{(*)+}_sD^{(*)-}_s$.
DOI: 10.1103/physrevd.83.071103
2011
Cited 26 times
Search for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>violation in the decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msubsup><mml:mi>K</mml:mi><mml:mi>S</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup></mml:math>
We report on a search for CP violation in the decay $ D^\pm \to K^0_{\scriptscriptstyle S} \pi^\pm $ using a data set corresponding to an integrated luminosity of $ 469\,\,fb^{-1} $ collected with the \slshape B\kern-0.1em{\smaller A}\kern-0.1em B\kern-0.1em{\smaller A\kern-0.2em R} detector at the PEP-II asymmetric energy $e^+e^-$ storage rings. The CPviolating decay rate asymmetry $A_{CP}$ is determined to be $(-0.44 \pm 0.13 \mathrm{(stat)} \pm 0.10 \mathrm{(syst)})%$, consistent with zero at 2.7 $\sigma$ and with the standard model prediction of $(-0.332 \pm 0.006)%$. This is currently the most precise measurement of this parameter.
DOI: 10.1103/physrevd.85.092017
2012
Cited 23 times
Observation and study of the baryonic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>-meson decays<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msup><mml:mi>D</mml:mi><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mo>*</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:msup><mml:mi>p</mml:mi><mml:mover accent="true"><mml:mi>p</mml:mi><mml:mo>¯</mml:mo></mml:…
We present results for B-meson decay modes involving a charm meson, protons, and pions using 455 x 10^6 BBbar pairs recorded by the BaBar detector at the SLAC PEP-II asymmetric-energy e+ e- collider. The branching fractions are measured for the following ten decays: B0bar to D0 p pbar, B0bar to D*0 p pbar, B0bar to D+ p pbar pi-, B0bar to D*+ p pbar pi-, B- to D0 p pbar pi-, B- to D*0 p pbar pi-, B0bar to D0 p pbar pi- pi+, B0bar to D*0 p pbar pi- pi+, B- to D+ p pbar pi- pi-, and B- to D*+ p pbar pi- pi-, The four B- and the two five-body B0bar modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(p pbar) and M(D(*)0 p) invariant mass distributions show enhancements near threshold values. In the four-body mode B0bar to D+ p pbar pi-, the M(p pi-) distribution shows a narrow structure of unknown origin near 1.5 GeV/c^2. The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.
DOI: 10.1103/physrevlett.107.041804
2011
Cited 23 times
Observation of the DecayB−→Ds(*)+K−ℓ−ν¯ℓ
We report the observation of the decay $B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}$ based on $342 \mathrm {\,fb}^{-1}}$ of data collected at the $\Y4S$ resonance with the BABAR detector at the PEP-II $e^{+}e^{-}$ storage rings at SLAC. A simultaneous fit to three $D^{+}_{s}$ decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay $B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}$ with a significance greater than five standard deviations (including systematic uncertainties) and measure its branching fraction to be $\BR(B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}) = [6.13^{+1.04}_{-1.03}(\mathrm{stat.})\pm0.43(\mathrm{syst.}) \pm 0.51(\BR(D_{s}))]\times10^{-4}$, where the last error reflects the limited knowledge of the $D_{s}$ branching fractions.
DOI: 10.1103/physrevd.83.091101
2011
Cited 20 times
Searches for the baryon- and lepton-number violating decays<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msubsup><mml:mi>Λ</mml:mi><mml:mi>c</mml:mi><mml:mo>+</mml:mo></mml:msubsup><mml:msup><mml:mi>l</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo…
Searches for $B$ mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either ${\ensuremath{\Lambda}}_{c}$ or $\ensuremath{\Lambda}$ and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range $(3.2--520)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ are set on the branching fractions at the 90% confidence level.
DOI: 10.1103/physrevd.90.092001
2014
Cited 19 times
Measurements of direct<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>asymmetries in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo stretchy="false">→</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mi>s</mml:mi></mml:msub><mml:mi>γ</mml:mi></mml:math>decays using sum of exclusive decays
We measure the direct CP violation asymmetry, A_CP, in B to X_s gamma and the isospin difference of the asymmetry, Delta A_CP, using 429 fb^-1 of data collected at Upsilon(4S) resonance with the BaBar detector at the PEP-II asymmetric-energy e+e- storage rings operating at the SLAC National Accelerator Laboratory. B mesons are reconstructed from 10 charged B final states and 6 neutral B final states. We find A_CP = +(1.7 +- 1.9 +- 1.0)%, which is in agreement with the Standard Model prediction and provides an improvement on the world average. Moreover, we report the first measurement of the difference between A_CP for charged and neutral decay modes, Delta A_CP = +(5.0 +- 3.9 +- 1.5)%. Using the value of Delta A_CP, we also provide 68% and 90% confidence intervals on the imaginary part of the ratio of the Wilson coefficients corresponding to the chromo-magnetic dipole and the electromagnetic dipole transitions.
DOI: 10.1103/physrevd.88.012003
2013
Cited 19 times
Measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>-violating asymmetries in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:mo stretchy="false">(</mml:mo><mml:mi>ρ</mml:mi><mml:mi>π</mml:mi><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mn>0</mml:mn></mml:msup></mml:math>decays using a time-dependent …
We present results for a time-dependent Dalitz plot measurement of CP-violating asymmetries in the mode B^0 -> pi^+ pi^- pi^0. The dataset is derived from the complete sample of 471 x 10^6 BBbar meson pairs collected with the BABAR detector at the PEP-II asymmetric-energy e^+e^- collider at the SLAC National Accelerator Laboratory operating on the Upsilon(4S) resonance. We extract parameters describing the time-dependent B^0 -> rho pi decay probabilities and CP asymmetries, including C = 0.016\pm0.059\pm0.036, DeltaC = 0.234\pm0.061\pm0.048, S = 0.053\pm0.081\pm0.034, and DeltaS = 0.054\pm0.082\pm0.039, where the uncertainties are statistical and systematic, respectively. We perform a two-dimensional likelihood scan of the direct CP-violation asymmetry parameters for B^0 -> rho^\pm pi^\mp decays, finding the change in chi^2 between the minimum and the origin (corresponding to no direct CP violation) to be Delta(chi^2)=6.42. We present information on the CP-violating parameter alpha in a likelihood scan that incorporates B^\pm -> rho pi measurements.
DOI: 10.1103/physrevlett.114.081801
2015
Cited 17 times
Study of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>Asymmetry in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>B</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup><mml:mtext>−</mml:mtext><mml:msup><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>B</mml:mi></mml:mrow><mml:mrow><mml:mo accent="true" stretchy="false">¯</mml:mo></mml:…
We present a measurement of the asymmetry A_{CP} between same-sign inclusive dilepton samples ℓ^{+}ℓ^{+} and ℓ^{-}ℓ^{-} (ℓ=e, μ) from semileptonic B decays in ϒ(4S)→BB[over ¯] events, using the complete data set recorded by the BABAR experiment near the ϒ(4S) resonance, corresponding to 471×10^{6} BB[over ¯] pairs. The asymmetry A_{CP} allows comparison between the mixing probabilities P(B[over ¯]^{0}→B^{0}) and P(B^{0}→B[over ¯]^{0}), and therefore probes CP and T violation. The result, A_{CP}=[-3.9±3.5(stat)±1.9(syst)]×10^{-3}, is consistent with the standard model expectation.
DOI: 10.1103/physrevd.107.052009
2023
Search for heavy neutral leptons using tau lepton decays at <i>BaBaR</i>
This article presents a model-independent search for an additional, mostly sterile, heavy neutral lepton (HNL), that is capable of mixing with the Standard Model $\ensuremath{\tau}$ neutrino with a mixing strength of $|{U}_{\ensuremath{\tau}4}{|}^{2}$, corresponding to the absolute square of the extended Pontecorvo-Maki-Nakagawa-Sakata matrix element. Data from the BABAR experiment, with a total integrated luminosity of $424\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, are analyzed using a kinematic approach that makes no assumptions on the model behind the origins of the HNL, its lifetime or decay modes. No significant signal is found. Upper limits on $|{U}_{\ensuremath{\tau}4}{|}^{2}$ at the 95% confidence level, depend on the HNL mass hypothesis and vary from $2.31\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$ to $5.04\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ (with all uncertainties considered), across the mass range $100&lt;{m}_{4}&lt;1300\text{ }\text{ }\mathrm{MeV}/{c}^{2}$; the more stringent limits being placed at higher masses.
DOI: 10.1103/physrevd.107.072001
2023
Study of the reactions <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>π</mml:…
We study the processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$, ${K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$, and ${K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\gamma}$ in which an energetic photon is radiated from the initial state. The data were collected with the BABAR detector at the SLAC National Accelerator Laboratory. About 1200, 2600, and 6000 events, respectively, are selected from a data sample corresponding to an integrated luminosity of $469\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. The invariant mass of the hadronic final state defines the effective ${e}^{+}{e}^{\ensuremath{-}}$ center-of-mass energy. The center-of-mass energies range from threshold to 4.5 GeV. From the mass spectra, the first ever measurements of the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$, ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$, and ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ cross sections are performed. The contributions from the intermediate states that include $\ensuremath{\eta}$, $\ensuremath{\phi}$, $\ensuremath{\rho}$, ${K}^{*}(892)$, and other resonances are presented. We observe the $J/\ensuremath{\psi}$ and $\ensuremath{\psi}(2S)$ in most of these final states and measure the corresponding branching fractions, many of them for the first time.
DOI: 10.1103/physrevd.108.l111103
2023
Measurement of additional radiation in the initial-state-radiation processes <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>μ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mi>γ</mml:mi></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/…
A dedicated measurement of additional radiation in e+e−→μ+μ−γ and e+e−→π+π−γ initial-state-radiation events is presented using the full BABAR data sample. For the first time results are presented at next-to- and next-to-next-to-leading order, with one and two additional photons, respectively, for radiation from the initial and final states. Comparison with predictions from phokhara and afkqed Monte Carlo generators is performed, revealing discrepancies in the one-photon rates and angular distributions for the former. This disagreement has a negligible effect on the BABAR measurement of the e+e−→π+π−(γ) cross section, but could affect other measurements significantly. This study sheds a new light on the longstanding discrepancy in this channel that affects the theoretical prediction of hadronic vacuum polarization contributions to the muon magnetic moment anomaly.1 MoreReceived 11 August 2023Revised 16 October 2023Accepted 14 November 2023DOI:https://doi.org/10.1103/PhysRevD.108.L111103Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasElectroweak interactionQuantum electrodynamicsParticles & Fields
DOI: 10.1103/physrevd.80.112002
2009
Cited 23 times
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>meson decays to charmless meson pairs containing<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>η</mml:mi></mml:math>or<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>η</mml:mi><mml:mo>′</mml:mo></mml:math>mesons
We present updated measurements of the branching fractions for B0 meson decays to etaK0, etaeta, etaphi, etaomega, eta'K0, eta'eta', eta'phi, and eta'omega, and branching fractions and CP-violating charge asymmetries for B+ decays to etapi+, etaK+, eta'pi+ and eta'K+. The data represent the full dataset of 467 10^{6} BB pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. Besides large signals for the four charged B decay modes and for B0\to eta'K0, we find evidence for three B0 decay modes at greater than 3.0sigma significance. We find B(B0\to etaK0) = (1.15^{+0.43}_{-0.38} \pm0.09)x10^{-6}, B(B0\to etaomega) = (0.94^{+0.35}_{-0.30}\pm0.09)x10^{-6}, and B(B0\to eta'omega) = (1.01^{+0.46}_{-0.38}\pm0.09)x10^{-6}, where the first (second) uncertainty is statistical (systematic). For the B+\to etaK+ decay mode, we measure the charge asymmetry A_{ch}(B+\to etaK+) = -0.36 \pm 0.11 \pm 0.03.
DOI: 10.1001/archinte.1977.03630170075017
1977
Cited 23 times
Heart Failure
Heart failure exists when either the systolic or diastolic operation of the ventricle is impaired to a degree that, despite compensatory mechanisms, the demands of the peripheral organs are not satisfied, the peripheral muscle shortens inadequately, and/or the pulmonary or systemic venous system becomes congested from high filling pressures. Since every pumping system has finite limits and can fail if excessive and prolonged demands are made on it, any definition of failure must take into consideration the degree of stress imposed and whether or not the cardiac response is appropriate or subnormal. When failure is present, it becomes essential to discern whether it involves the intrinsic pumping structures of the heart, the myocardial cells, or, rather, whether failure of one of the other components of the integrated cardiovascular system (for example, valvular dysfunction, ruptured ventricular septum) has occurred. (<i>Arch Intern Med</i>137:675-678, 1977)
DOI: 10.1103/physrevd.80.111105
2009
Cited 21 times
Model-independent search for the decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>l</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msub><mml:mi>ν</mml:mi><mml:mi>l</mml:mi></mml:msub><mml:mi>γ</mml:mi></mml:math>
We present a search for the radiative leptonic decay ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}\ensuremath{\gamma}$, where $\ensuremath{\ell}=e$, $\ensuremath{\mu}$, using a data sample of $465\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected by the BABAR experiment. In this analysis, we fully reconstruct the hadronic decay of one of the $B$ mesons in $\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}{B}^{+}{B}^{\ensuremath{-}}$ decays, then search for evidence of ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}\ensuremath{\gamma}$ in the rest of the event. We observe no significant evidence of signal decays and report model-independent branching fraction upper limits of $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\nu}}_{e}\ensuremath{\gamma})&lt;17\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\gamma})&lt;24\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, and $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}\ensuremath{\gamma})&lt;15.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ ($\ensuremath{\ell}=e$ or $\ensuremath{\mu}$), all at the 90% confidence level.
DOI: 10.1103/physrevlett.104.151802
2010
Cited 21 times
Search for Charged Lepton Flavor Violation in Narrow<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Υ</mml:mi></mml:math>Decays
Charged-lepton flavor-violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99x10(6)Upsilon(2S) decays and 117x10(6)Upsilon(3S) decays collected with the BABAR detector. We place upper limits on the branching fractions B(Upsilon(nS)-->e(+/-)tau(-/+)) and B(Upsilon(nS)-->mu(+/-)tau(-/+)) (n=2,3) at the 10(-6) level and use these results to place lower limits of order 1 TeV on the mass scale of charged-lepton flavor-violating effective operators.
DOI: 10.1103/physrevd.86.091102
2012
Cited 18 times
Study of the baryonic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msubsup><mml:mi mathvariant="italic">Σ</mml:mi><mml:mi>c</mml:mi><mml:mo>++</mml:mo></mml:msubsup><mml:mover accent="true"><mml:mi>p</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo…
We report the measurement of the baryonic B decay B- -> SigmaC++ p- pi- pi-. Using a data sample of 467*10^6 B B-bar pairs collected with the BaBar detector at the PEP-II storage ring at SLAC, the measured branching fraction is (2.98 +/- 0.16 (stat) +/- 0.15 (syst) +/- 0.77 (LambdaC+))*10^{-4}, where the last error is due to the uncertainty in the branching fraction of the decay LambdaC+ -> p+ K- pi+. The data suggest the existence of resonant subchannels B- -> LambdaC(2595)+ p- pi- and, possibly, B- -> SigmaC++ anti-Delta-- pi-. We see unexplained structures in m(SigmaC++ pi- pi-) at 3.25 GeV/c^2, 3.8 GeV/c^2, and 4.2 GeV/c^2.
DOI: 10.1103/physrevd.88.052003
2013
Cited 18 times
Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mo>*</mml:mo></mml:msup><mml:mo stretchy="false">(</mml:mo><mml:mn>2010</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo mathvariant="bold">+</mml:mo></mml:msup></mml:math>natural linewidth and the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mo>*</mml:mo></mml:msup><mml:mo stretchy="false">(</mml:mo…
We measure the mass difference, $\ensuremath{\Delta}{m}_{0}$, between the ${D}^{*}(2010{)}^{+}$ and the ${D}^{0}$ and the natural linewidth, $\ensuremath{\Gamma}$, of the transition ${D}^{*}(2010{)}^{+}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{+}$. The data were recorded with the BABAR detector at center-of-mass energies at and near the $\ensuremath{\Upsilon}(4S)$ resonance, and correspond to an integrated luminosity of approximately $477\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. The ${D}^{0}$ is reconstructed in the decay modes ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ and ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$. For the decay mode ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ we obtain $\ensuremath{\Gamma}=(83.4\ifmmode\pm\else\textpm\fi{}1.7\ifmmode\pm\else\textpm\fi{}1.5)\text{ }\text{ }\mathrm{keV}$ and $\ensuremath{\Delta}{m}_{0}=(145425.6\ifmmode\pm\else\textpm\fi{}0.6\ifmmode\pm\else\textpm\fi{}1.8)\text{ }\text{ }\mathrm{keV}$, where the quoted errors are statistical and systematic, respectively. For the ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ mode we obtain $\ensuremath{\Gamma}=(83.2\ifmmode\pm\else\textpm\fi{}1.5\ifmmode\pm\else\textpm\fi{}2.6)\text{ }\text{ }\mathrm{keV}$ and $\ensuremath{\Delta}{m}_{0}=(145426.6\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}2.0)\text{ }\text{ }\mathrm{keV}$. The combined measurements yield $\ensuremath{\Gamma}=(83.3\ifmmode\pm\else\textpm\fi{}1.2\ifmmode\pm\else\textpm\fi{}1.4)\text{ }\text{ }\mathrm{keV}$ and $\ensuremath{\Delta}{m}_{0}=(145425.9\ifmmode\pm\else\textpm\fi{}0.4\ifmmode\pm\else\textpm\fi{}1.7)\text{ }\text{ }\mathrm{keV}$; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.
DOI: 10.1103/physrevd.88.031701
2013
Cited 18 times
Search for a light Higgs boson decaying to two gluons orss¯in the radiative decays ofΥ(1S)
We search for the decay $\mathit{\ensuremath{\Upsilon}}(1S)\ensuremath{\rightarrow}\ensuremath{\gamma}{A}^{0}$, ${A}^{0}\ensuremath{\rightarrow}gg$ or $\mathrm{s}\overline{\mathrm{s}}$, where ${A}^{0}$ is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric Standard Model. We use a sample of $(17.6\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\mathit{\ensuremath{\Upsilon}}(1S)$ mesons produced in the BABAR experiment via ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathit{\ensuremath{\Upsilon}}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\mathit{\ensuremath{\Upsilon}}(1S)$. We see no significant signal and set 90%-confidence-level upper limits on the product branching fraction $\mathcal{B}(\mathit{\ensuremath{\Upsilon}}(1S)\ensuremath{\rightarrow}\ensuremath{\gamma}{A}^{0})\ifmmode\cdot\else\textperiodcentered\fi{}\mathcal{B}({A}^{0}\ensuremath{\rightarrow}gg\text{ }\mathrm{\text{or}}\text{ }\mathrm{s}\overline{\mathrm{s}})$ ranging from ${10}^{\ensuremath{-}6}$ to ${10}^{\ensuremath{-}2}$ for ${A}^{0}$ masses in the range $0.5--9.0\text{ }\text{ }\mathrm{GeV}/{c}^{2}$.
DOI: 10.1103/physrevd.84.072002
2011
Cited 17 times
Study of radiative bottomonium transitions using converted photons
We use (111±1) million Υ(3S) and (89±1) million Υ(2S) events recorded by the BABAR detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions between bottomonium states using photons that have been converted to e+e− pairs by the detector material. We observe Υ(3S)→γχb0,2(1P) decay, make precise measurements of the branching fractions for χb1,2(1P,2P)→γΥ(1S) and χb1,2(2P)→γΥ(2S) decays, and search for radiative decay to the ηb(1S) and ηb(2S) states.1 MoreReceived 27 April 2011Corrected 18 October 2011DOI:https://doi.org/10.1103/PhysRevD.84.072002© 2011 American Physical Society
DOI: 10.1103/physrevd.87.032004
2013
Cited 17 times
Branching fraction measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>ω</mml:mi><mml:msup><mml:mi>ℓ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mi>ν</mml:mi></mml:math>decays
We present a measurement of the B -> omega l nu branching fraction based on a sample of 467 million BB pairs recorded by the BaBar detector at the SLAC PEP-2 e+e- collider. We observe 1125 +- 131 signal decays, corresponding to a branching fraction of BF(B -> omega l nu) = (1.21 +- 0.14 +- 0.08) x 10^{-4}, where the first error is statistical and the second is systematic. The dependence of the decay rate on q^2, the momentum transfer squared to the lepton system, is compared to QCD predictions of the form factors based on a quark model and light-cone sum rules.
DOI: 10.1103/physrevd.84.092007
2011
Cited 17 times
Observation of the rare decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>and measurement of the quasi-two-body contributions<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml…
We report an analysis of the charmless hadronic decays of charged B meson to the final state K+pi0pi0, using a data sample of 470+/-2.8 million BBbar events collected at the Y(4S) resonance. We observe an excess of signal events, with a significance above 10 standard deviations including systematic uncertainties, and measure the branching fraction and CP asymmetry to be B(B+->K+pi0pi0)=(16.2+/-1.2+/-1.5)x10^-6 and A_CP(B+->K+pi0pi0)=-0.06+/-0.06+/-0.04, where the uncertainties are statistical and systematic respectively. Additionally we study the contributions of the B+->K*(892)+pi0, B+->f0(980)K+ and B+->chic0K+ quasi-two body decays. We report the world's best measurements of the branching fractions and CP asymmetry of the B+->K+pi0pi0 and B+->K*(892)+pi0 channels.
DOI: 10.1103/physrevd.92.072008
2015
Cited 15 times
Study of thee+e−→K+K−reaction in the energy range from 2.6 to 8.0 GeV
The $e^+e^-\to K^+K^-$ cross section and charged-kaon electromagnetic form factor are measured in the $e^+e^-$ center-of-mass energy range ($E$) from 2.6 to 8.0 GeV using the initial-state radiation technique with an undetected photon. The study is performed using 469 fb$^{-1}$ of data collected with the BABAR detector at the PEP-II $e^+e^-$ collider at center-of-mass energies near 10.6 GeV. The form factor is found to decrease with energy faster than $1/E^2$, and approaches the asymptotic QCD prediction. Production of the $K^+K^-$ final state through the $J/\psi$ and $\psi(2S)$ intermediate states is observed. The results for the kaon form factor are used together with data from other experiments to perform a model-independent determination of the relative phases between single-photon and strong amplitudes in $J/\psi$ and $\psi(2S)\to K^+K^-$ decays. The values of the branching fractions measured in the reaction $e^+e^- \to K^+K^-$ are shifted relative to their true values due to interference between resonant and nonresonant amplitudes. The values of these shifts are determined to be about $\pm5\%$ for the $J/\psi$ meson and $\pm15\%$ for the $\psi(2S)$ meson.
DOI: 10.1103/physrevlett.116.041801
2016
Cited 15 times
Observation of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>B</mml:mi></mml:mrow><mml:mrow><mml:mo stretchy="false">¯</mml:mo></mml:mrow></mml:mover><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mo>*</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:msup><mml:mtext> </mml:mtext><mml:msup><mml:mrow><mml:mi>π</mml:mi></…
We report on measurements of the decays of B¯ mesons into the semileptonic final states B¯→D^(*)π^(+)π^(-)ℓ^(-)ν¯, where D^(*) represents a D or D^(*) meson and ℓ^(-) is an electron or a muon. These measurements are based on 471×10^(6) BB ¯ pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R_{π^{+}π^{-}}^{(*)}=B(B[over ¯]→D^{(*)}π^{+}π^{-}ℓ^{-}ν[over ¯])/B(B[over ¯]→D^{(*)}ℓ^{-}ν[over ¯]) using events in which the second B meson is fully reconstructed. We find R_{π^{+}π^{-}}=0.067±0.010±0.008 and R_{π^{+}π^{-}}^{*}=0.019±0.005±0.004, where the first uncertainty is statistical and the second is systematic. Based on these results and assuming isospin invariance, we estimate that B[over ¯]→D^{(*)}ππℓ^{-}ν[over ¯] decays, where π denotes either a π^{±} and π^{0} meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions.
DOI: 10.1103/physrevd.93.052013
2016
Cited 14 times
Time-dependent analysis of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msubsup><mml:mi>K</mml:mi><mml:mi>S</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mi>γ</mml:mi></mml:math>decays and studies of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" …
We measure the time-dependent $CP$ asymmetry in the radiative-penguin decay ${B}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}\ensuremath{\gamma}$, using a sample of $471\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\mathrm{\ensuremath{\Upsilon}}(4S)\ensuremath{\rightarrow}B\overline{B}$ events recorded with the BABAR detector at the PEP-II ${e}^{+}{e}^{\ensuremath{-}}$ storage ring at SLAC. Using events with ${m}_{K\ensuremath{\pi}\ensuremath{\pi}}&lt;1.8\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, we measure the branching fractions of ${B}^{+}\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}\ensuremath{\gamma}$ and ${B}^{0}\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}\ensuremath{\gamma}$, the branching fractions of the kaonic resonances decaying to ${K}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, as well as the overall branching fractions of the ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}{K}^{+}\ensuremath{\gamma}$, ${B}^{+}\ensuremath{\rightarrow}{K}^{*0}{\ensuremath{\pi}}^{+}\ensuremath{\gamma}$ and $S$-wave ${B}^{+}\ensuremath{\rightarrow}(K\ensuremath{\pi}{)}_{0}^{*0}{\ensuremath{\pi}}^{+}\ensuremath{\gamma}$ components. For events from the $\ensuremath{\rho}$ mass band, we measure the $CP$-violating parameters ${\mathcal{S}}_{{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\gamma}}=0.14\ifmmode\pm\else\textpm\fi{}0.25\ifmmode\pm\else\textpm\fi{}0.03$ and ${\mathcal{C}}_{{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\gamma}}=\ensuremath{-}0.39\ifmmode\pm\else\textpm\fi{}0.2{0}_{\ensuremath{-}0.02}^{+0.03}$, where the first uncertainties are statistical and the second are systematic. We extract from this measurement the time-dependent $CP$ asymmetry related to the $CP$ eigenstate ${\ensuremath{\rho}}^{0}{K}_{S}^{0}$ and obtain ${\mathcal{S}}_{{K}_{S}^{0}\ensuremath{\rho}\ensuremath{\gamma}}=\ensuremath{-}0.18\ifmmode\pm\else\textpm\fi{}0.3{2}_{\ensuremath{-}0.05}^{+0.06}$, which provides information on the photon polarization in the underlying $b\ensuremath{\rightarrow}s\ensuremath{\gamma}$ transition.
DOI: 10.1103/physrevd.84.031103
2011
Cited 16 times
Search for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>violation using<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>T</mml:mi></mml:math>-odd correlations in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msubsup><mml:mi>K</…
We search for CP violation in a sample of 20000 Cabibbo-suppressed decays, $D^+\rightarrow K^+K^0_S\pi^+\pi^-$, and 30000 Cabibbo-favored decays, $D_s^+\rightarrow K^+K^0_S\pi^+\pi^-$. We use 520 $fb^{-1}$ of data recorded by the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ collider operating at center of mass energies near 10.6 $GeV$. We search for CP violation in the difference between the $T$-odd asymmetries obtained using triple product correlations of the $D^+$ ($D_s^+$) and $D^-$ ($D_s^-$) decays, respectively. The $T$ violation parameter values obtained are $\mathcal{A}_T(D^+) = (-12.0 \pm 10.0_{stat} \pm 4.6_{syst})\times 10^{-3}$ and $\mathcal{A}_T(D_s^+) = (-13.6 \pm 7.7_{stat} \pm 3.4_{syst}) \times10^{-3}$, which are consistent with the standard model expectations.
DOI: 10.1103/physrevd.85.011101
2012
Cited 15 times
Measurement of the semileptonic branching fraction of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>B</mml:mi><mml:mi>s</mml:mi></mml:msub></mml:math>meson
We report a measurement of the inclusive semileptonic branching fraction of the B_s meson using data collected with the BaBar detector in the center-of-mass (CM) energy region above the Upsilon(4S) resonance. We use the inclusive yield of phi mesons and the phi yield in association with a high-momentum lepton to perform a simultaneous measurement of the semileptonic branching fraction and the production rate of B_s mesons relative to all B mesons as a function of CM energy. The inclusive semileptonic branching fraction of the B_s meson is determined to be B(B_s to l nu X)=9.5 (+2.5/-2.0)(stat)(+1.1/-1.9)(syst)%, where l indicates the average of e and mu.
DOI: 10.1103/physrevd.89.111102
2014
Cited 14 times
Antideuteron production in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="italic">ϒ</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>n</mml:mi><mml:mi>S</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math>decays and in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:…
We present measurements of the inclusive production of antideuterons in $e^+e^-$ annihilation into hadrons at $\approx 10.58 \mathrm{\,Ge\kern -0.1em V}$ center-of-mass energy and in $\Upsilon(1S,2S,3S)$ decays. The results are obtained using data collected by the BABAR detector at the PEP-II electron-positron collider. Assuming a fireball spectral shape for the emitted antideuteron momentum, we find $\mathcal{B}(\Upsilon(1S) \to \bar{d}X) = (2.81 \pm 0.49 \mathrm{(stat)} {}^{+0.20}_{-0.24} \mathrm{(syst)})/! \times /! 10^{-5}$, $\mathcal{B}(\Upsilon(2S) \to \bar{d}X) = (2.64 \pm 0.11 \mathrm{(stat)} {}^{+0.26}_{-0.21} \mathrm{(syst)})/! \times /! 10^{-5}$, $\mathcal{B}(\Upsilon(3S) \to \bar{d}X) = (2.33 \pm 0.15 \mathrm{(stat)} {}^{+0.31}_{-0.28} \mathrm{(syst)})/! \times /! 10^{-5}$, and $\sigma (e^+e^- \to \bar{d}X) = (9.63 \pm 0.41 \mathrm{(stat)} {}^{+1.17}_{-1.01} \mathrm{(syst)}) \mbox{\,fb}$.
DOI: 10.1103/physrevd.93.112014
2016
Cited 12 times
Measurement of the neutral<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>D</mml:mi></mml:mrow></mml:math>meson mixing parameters in a time-dependent amplitude analysis of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><…
We perform the first measurement on the ${D}^{0}\ensuremath{-}{\overline{D}}^{0}$ mixing parameters using a time-dependent amplitude analysis of the decay ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$. The data were recorded with the BABAR detector at center-of-mass energies at and near the $\ensuremath{\Upsilon}(4S)$ resonance, and correspond to an integrated luminosity of approximately $468.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. The neutral $D$ meson candidates are selected from ${D}^{*}(2010{)}^{+}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}_{s}^{+}$ decays where the flavor at the production is identified by the charge of the low-momentum pion, ${\ensuremath{\pi}}_{s}^{+}$. The measured mixing parameters are $x=(1.5\ifmmode\pm\else\textpm\fi{}1.2\ifmmode\pm\else\textpm\fi{}0.6)%$ and $y=(0.2\ifmmode\pm\else\textpm\fi{}0.9\ifmmode\pm\else\textpm\fi{}0.5)%$, where the quoted uncertainties are statistical and systematic, respectively.
DOI: 10.1097/00000542-199507000-00024
1995
Cited 25 times
Factitious Disorder as a Cause of Failure to Awaken after General Anesthesia
(Albrecht II, Wagner) Resident in Anesthesiology.(Leicht) Assistant Professor of Anesthesiology.(Lanier) Associate Professor of Anesthesiology.Received from the Department of Anesthesiology, Mayo Clinic and Mayo Medical School, Rochester, Minnesota. Submitted for publication September 26, 1994. Accepted for publication March 6, 1995.Address reprint requests to Dr. Lanier: Department of Anesthesiology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905.Key words: Anesthesia: depth. Psychologic responses.FAILURE of a patient to awaken after general anesthesia may involve a complex array of etiologies that includes several life-threatening disease states. [1-3]The potential for patient harm requires the anesthesiologist to rapidly diagnose and, if needed, treat (or arrange treatment for) any underlying pathology. Although factitious disorders are rarely the cause of delayed emergence, patient unwillingness to awaken after anesthesia is a recognized occurrence that is, by necessity, a diagnosis of exclusion. [1].We report two patients who failed to progressively awaken after general anesthesia for minor surgical procedures. Both patients had normal neurologic examination results, and serious complications related to the surgery and the anesthetic were ruled out. One patient had a history of psychiatric disorders; the other did not. In both, the failure to awaken was believed to be secondary to factitious disorders.A 36-yr-old, 53-kg woman, ASA physical status 2, was scheduled for general anesthesia for an intranasal ethmoidectomy with middle meatal antrostomies for recurrent sinusitis. She had had juvenile onset diabetes mellitus for 21 yr with resultant retinopathy and peripheral neuropathy. Preoperative medications included Lente insulin 10 U subcutaneously every 8 h, terfenadine, and pseudoephedrine.Seven years before surgery, the patient exhibited prolonged postoperative paresis after straightforward removal of a ganglion cyst under general anesthesia. An underlying organic or pharmacologic disorder was never identified. Four years before surgery, she was diagnosed with a conversion disorder. This was based on three episodes of burning pain of her right extremities accompanied by unexplained, self-limited paresis. At that time, her Minnesota multiphasic personality inventory (MMPI) [4]evaluation exhibited features consistent with histrionic behavior. Specifically, she demonstrated a tendency to exaggerate signs and symptoms of disease.After placement of routine physiologic monitors, the patient was sedated with 6 mg intravenous morphine, and anesthesia was induced with 450 mg intravenous thiopental. After neuromuscular block with 80 mg intravenous succinylcholine, the trachea was intubated with a 7.0 mm-ID cuffed endotracheal tube. Ventilation was mechanically controlled, and anesthesia was maintained with inhaled enflurane and nitrous oxide in oxygen for the duration of surgery.The operative course was uneventful. On conclusion of the surgical procedure, the patient breathed spontaneously with a normal respiratory rate and an adequate tidal volume (350 ml, estimated). The end-tidal enflurane concentration, measured by mass spectrometry, was 0.18%. Although the patient would not respond to verbal commands, she demonstrated clinically the ability to protect her airway by vigorous, repeated swallowing as well as purposeful motor activity (right upper extremity movement presumably directed to self-extubate her trachea). Accordingly, the trachea was extubated, by the anesthesiologist, without complication.The patient was moved to a transport cart, and supplemental oxygen was supplied (FIO2= 1.0) for the duration of transfer to the post-anesthetic care unit (PACU). Once in the PACU, routine postoperative monitors were applied, and oxygen was delivered by a face shield (FIO2= 0.4). The patient continued to ventilate normally, however, she would not respond to verbal prompts, touch, or pain (sternal rub). Her hemodynamic variables remained stable. Pupil size was within normal limits, and funduscopic examination did not demonstrate the presence of papilledema. Serum electrolytes, blood glucose, and body temperature were normal. Hemoglobin oxygen saturation (measured by pulse oximetry) was > 96% throughout the postoperative period.After 90 min in the PACU, the staff anesthesiologist became concerned that the patient showed no signs of progressive awakening, and an underlying cause could not be identified. In response to a request for consultation, a neurologist performed a detailed neurologic examination and found that, although the patient was unresponsive, her neurologic status was otherwise within normal limits. At the conclusion of his examination, the neurologist thought he could see the patient looking surreptitiously at her surroundings when no one stood at her bedside. He repeated the neurologic evaluation with the same result: i.e., the patient was completely unresponsive to noxious stimulation. He observed the patient closely as he wrote his note and, a few moments later, discovered that she covertly glanced around the PACU. He approached the patient again and injected ice water into her left ear, consistent with the vestibulo-ocular reflex test. The patient sat bolt upright on her cart and exclaimed,
DOI: 10.1103/physrevd.84.092003
2011
Cited 14 times
Study of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">Υ</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>3</mml:mn><mml:mi>S</mml:mi><mml:mo>,</mml:mo><mml:mn>2</mml:mn><mml:mi>S</mml:mi><mml:mo stretchy="false">)</mml:mo><mml:mo>→</mml:mo><mml:mi>η</mml:mi><mml:mi mathvariant="italic">Υ</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>1</mml:mn><mml:mi>S</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math>and<mml:math xmlns:mml="…
We study the $\mathit{\ensuremath{\Upsilon}}(3S,2S)\ensuremath{\rightarrow}\ensuremath{\eta}\mathit{\ensuremath{\Upsilon}}(1S)$ and $\mathit{\ensuremath{\Upsilon}}(3S,2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\mathit{\ensuremath{\Upsilon}}(1S)$ transitions with $122\ifmmode\times\else\texttimes\fi{}{10}^{6}\mathit{\ensuremath{\Upsilon}}(3S)$ and $100\ifmmode\times\else\texttimes\fi{}{10}^{6}\mathit{\ensuremath{\Upsilon}}(2S)$ mesons collected by the BABAR detector at the PEP-II asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. We measure $\mathcal{B}[\mathit{\ensuremath{\Upsilon}}(2S)\ensuremath{\rightarrow}\ensuremath{\eta}\mathit{\ensuremath{\Upsilon}}(1S)]=(2.39\ifmmode\pm\else\textpm\fi{}0.31(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.14(\mathrm{syst}.))\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and $\ensuremath{\Gamma}[\mathit{\ensuremath{\Upsilon}}(2S)\ensuremath{\rightarrow}\ensuremath{\eta}\mathit{\ensuremath{\Upsilon}}(1S)]/\ensuremath{\Gamma}[\mathit{\ensuremath{\Upsilon}}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\mathit{\ensuremath{\Upsilon}}(1S)]=(1.35\ifmmode\pm\else\textpm\fi{}0.17(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.08(\mathrm{syst}.))\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$. We find no evidence for $\mathit{\ensuremath{\Upsilon}}(3S)\ensuremath{\rightarrow}\ensuremath{\eta}\mathit{\ensuremath{\Upsilon}}(1S)$ and obtain $\mathcal{B}[\mathit{\ensuremath{\Upsilon}}(3S)\ensuremath{\rightarrow}\ensuremath{\eta}\mathit{\ensuremath{\Upsilon}}(1S)]&lt;1.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and $\ensuremath{\Gamma}[\mathit{\ensuremath{\Upsilon}}(3S)\ensuremath{\rightarrow}\ensuremath{\eta}\mathit{\ensuremath{\Upsilon}}(1S)]/\phantom{\rule{0ex}{0ex}}\ensuremath{\Gamma}[\mathit{\ensuremath{\Upsilon}}(3S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\mathit{\ensuremath{\Upsilon}}(1S)]&lt;2.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ as upper limits at the 90% confidence level. We also provide improved measurements of the $\mathit{\ensuremath{\Upsilon}}(2S)\ensuremath{-}\mathit{\ensuremath{\Upsilon}}(1S)$ and $\mathit{\ensuremath{\Upsilon}}(3S)\ensuremath{-}\mathit{\ensuremath{\Upsilon}}(1S)$ mass differences, $562.170\ifmmode\pm\else\textpm\fi{}0.007(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.088(\mathrm{syst}.)\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and $893.813\ifmmode\pm\else\textpm\fi{}0.015(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}0.107(\mathrm{syst}.)\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, respectively.
DOI: 10.1103/physrevd.87.052010
2013
Cited 13 times
Search for direct<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>violation in singly Cabibbo-suppressed<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mo mathvariant="bold">±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo mathvariant="bold">+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><…
We report on a search for direct $CP$ violation in the singly Cabibbo-suppressed decay ${D}^{+}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ using a data sample of $476\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data accumulated with the BABAR detector at the SLAC PEP-II electron-positron collider, running at and just below the energy of the $\ensuremath{\Upsilon}(4S)$ resonance. The integrated $CP$-violating decay rate asymmetry ${A}_{CP}$ is determined to be $(0.37\ifmmode\pm\else\textpm\fi{}0.30\ifmmode\pm\else\textpm\fi{}0.15)%$. Model-independent and model-dependent Dalitz plot analysis techniques are used to search for $CP$-violating asymmetries in the various intermediate states. We find no evidence for $CP$-violation asymmetry.
DOI: 10.1016/0370-2693(85)90635-5
1985
Cited 20 times
Inclusive neutral D∗ production and limits on F∗ production in e+e− annihilations at petra
D∗0 mesons, produced in e+e− annihilations, are observed in the γD0 and π0D0 decay modes, where the D0 subsequently decays into K−π+. The production cross section and the xE distribution for D∗0 mesons are extracted from the data, and compared with corresponding measurements for D∗+ mesons. The branching ratio for the D∗0 radiative decay is measured to be 0.53 ± 0.13. An upper limit for the σ · BR of the F∗+ meson, where the associated F+ decays into φπ+, is also derived.
DOI: 10.1016/0168-9002(87)91216-2
1987
Cited 20 times
Trigger drift chamber for the upgraded mark II detector at PEP
Abstract A small cylindrical track detector was built as an array of single-wire drift cells with aluminized mylar cathode tubes. Point measurement resolution of ∼ 90 μm was achieved with a drift gas of 50% argon-50% ethane at atmospheric pressure. The chamber construction, electronics, and calibration are discussed. Performance results from PEP colliding-beam data are presented.
DOI: 10.1103/physrevd.82.011502
2010
Cited 12 times
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>-meson decays to<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>η</mml:mi><mml:mo>′</mml:mo></mml:msup><mml:mi>ρ</mml:mi></mml:math>,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>η</mml:mi><mml:mo>′</mml:mo></mml:msup><mml:msub><mml:mi>f</mml:mi><mml:mn>0</mml:mn></mml:msub></mml:math>, and<mml:math xmlns…
We present measurements of B-meson decays to the final states eta'rho, eta'f0, and eta'K*, where K* stands for a vector, scalar, or tensor strange meson. We observe a significant signal or evidence for eta'rho+ and all the eta'K* channels. We also measure, where applicable, the charge asymmetries, finding results consistent with no direct CP-violation in all cases. The measurements are performed on a data sample consisting of 467 x 10^6 B-Bbar pairs, collected with the BaBar detector at the PEP-II e+e- collider at the SLAC National Accelerator Laboratory. Our results favor the theoretical predictions from perturbative QCD and QCD Factorization and we observe an enhancement of the tensor K_2*(1430) with respect to the vector K*(892) component.
DOI: 10.1103/physrevd.85.099904
2012
Cited 10 times
Erratum: Search for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>violation in the decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo mathvariant="bold">−</mml:mo></mml:msup><mml:msubsup><mml:mi>K</mml:mi><mml:mi>s</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:mo …
DOI: 10.1103/physrevd.91.019901
2015
Cited 9 times
Erratum: Measurement of the absolute branching fractions for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mo>−</mml:mo></mml:msubsup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mo>ℓ</mml:mo><mml:mo>−</mml:mo></mml:msup><mml:msub><mml:mover accent="true"><mml:mi>ν</mml:mi><mml:mo accent="true" stretchy="false">¯</mml:mo></mml:mover><mml:mo>ℓ</mml:mo></mml:msub></mml:math>and extraction of the decay constant<…
Received 16 December 2014DOI:https://doi.org/10.1103/PhysRevD.91.019901© 2015 American Physical Society
DOI: 10.1103/physrevd.82.031101
2010
Cited 11 times
Observation of the rare decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msubsup><mml:mi>K</mml:mi><mml:mi>S</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>∓</mml:mo></mml:msup></mml:math>
We report an analysis of charmless hadronic decays of neutral B mesons to the final state KsK+/-pi-/+, using a data sample of (465 +/- 5) x 10^6 BB-bar events collected with the BABAR detector at the Y(4S) resonance. We observe an excess of signal events with a significance of 5.2 standard deviations including systematic uncertainties and measure the branching fraction to be BF(B0 --> KsK+/-pi-/+) = (3.2 +/- 0.5 +/- 0.3) x 10^-6, where the uncertainties are statistical and systematic, respectively.
DOI: 10.1103/physrevd.84.012001
2011
Cited 10 times
Measurements of branching fractions and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>asymmetries and studies of angular distributions for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:mi>ϕ</mml:mi><mml:mi>ϕ</mml:mi><mml:mi>K</mml:mi></mml:math>decays
We present branching fraction and CP asymmetry measurements as well as angular studies of B to phi phi K decays using 464 x 10^6 BBbar events collected by the BaBar experiment. The branching fractions are measured in the phi phi invariant mass range below the eta_c resonance (m_phiphi &lt;2.85 GeV). We find B(B+ to phi phi K+) = (5.6 +/- 0.5 +/- 0.3) x 10^-6 and B(B0 to phi phi K0) = (4.5 +/- 0.8 +/- 0.3) x 10^-6, where the first uncertaintiy is statistical and the second systematic. The measured direct CP asymmetries for the B+- decays are A_CP = -0.10 +/- 0.08 +/- 0.02 below the eta_c threshold and A_CP = 0.09 +/- 0.10 +?- 0.02 in the eta_c resonance region (m_phiphi in [2.94,3.02] GeV). Angular distributions are consistent with J^P = 0- in the eta_c resonance region and favor J^P = 0+ below the eta_c resonance.
DOI: 10.1103/physrevlett.122.081802
2019
Cited 8 times
Observation of the Decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>
We report the observation of the rare charm decay ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{e}^{+}{e}^{\ensuremath{-}}$, based on $468\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data collected at or close to the center-of-mass energy of the $\mathrm{\ensuremath{\Upsilon}}(4\mathrm{S})$ resonance with the BABAR detector at the SLAC National Accelerator Laboratory. We find the branching fraction in the invariant mass range $0.675&lt;m({e}^{+}{e}^{\ensuremath{-}})&lt;0.875\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ of the electron-positron pair to be $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{e}^{+}{e}^{\ensuremath{-}})=\phantom{\rule{0ex}{0ex}}(4.0\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.2\ifmmode\pm\else\textpm\fi{}0.1)\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}6}$, where the first uncertainty is statistical, the second systematic, and the third due to the uncertainty in the branching fraction of the decay ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ used as a normalization mode. The significance of the observation corresponds to 9.7 standard deviations including systematic uncertainties. This result is consistent with the recently reported ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ branching fraction, measured in the same invariant mass range, and with the value expected in the standard model. In a set of regions of $m({e}^{+}{e}^{\ensuremath{-}})$, where long-distance effects are potentially small, we determine a 90% confidence level upper limit on the branching fraction $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{e}^{+}{e}^{\ensuremath{-}})&lt;3.1\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}6}$.
DOI: 10.1103/physrevd.80.092007
2009
Cited 9 times
Observation and polarization measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msub><mml:mi>a</mml:mi><mml:mn>1</mml:mn></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>1260</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo>+</mml:mo></mml:msup><mml:msub><mml:mi>a</mml:mi><mml:mn>1</mml:mn></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>1260</mml:mn><mml:…
We present measurements of the branching fraction B and the longitudinal polarization fraction fL for B0 -> a1(1260)+ a1(1260)- decays, with a1(1260)+/- -> \pi- \pi+ \pi+/-. The data sample, collected with the detector BaBar at the SLAC National Accelerator Laboratory, represents 465 10^6 produced BBbar pairs. We measure B(B0 -> a1(1260)+ a1(1260)-) x [B(a1(1260)+ -> \pi- \pi+ \pi+)]^2 = (11.8 \pm 2.6 \pm 1.6) 10^{-6} and fL = 0.31 \pm 0.22 \pm 0.10, where the first uncertainty is statistical and the second systematic. The decay mode is measured with a significance of 5.0 standard deviations including systematic uncertainties.
DOI: 10.1103/physrevlett.103.041802
2009
Cited 9 times
Search for Second-Class Currents in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>ω</mml:mi><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msub><mml:mi>ν</mml:mi><mml:mi>τ</mml:mi></mml:msub></mml:math>
We report an analysis of ${\ensuremath{\tau}}^{\ensuremath{-}}$ decaying into $\ensuremath{\omega}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ with $\ensuremath{\omega}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ using a data sample containing nearly $320\ifmmode\times\else\texttimes\fi{}{10}^{6}\ensuremath{\tau}$ pairs collected with the BABAR detector at the PEP-II $B$-Factory. We find no evidence for second-class currents, and we set an upper limit of 0.69% at 90% confidence level for the fraction of second-class currents in this decay mode.
DOI: 10.1103/physrevd.82.031102
2010
Cited 9 times
Observation of the decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mover accent="true"><mml:mi>B</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mn>0</mml:mn></mml:msup><mml:mo>→</mml:mo><mml:msubsup><mml:mi mathvariant="italic">Λ</mml:mi><mml:mi>c</mml:mi><mml:mo>+</mml:mo></mml:msubsup><mml:mover accent="true"><mml:mi>p</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>
In a sample of $467\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected with the BABAR detector at the PEP-II collider at SLAC we have observed the decay ${\overline{B}}^{0}\ensuremath{\rightarrow}{\mathit{\ensuremath{\Lambda}}}_{c}^{+}\overline{p}{\ensuremath{\pi}}^{0}$ and measured the branching fraction to be $(1.94\ifmmode\pm\else\textpm\fi{}0.17\ifmmode\pm\else\textpm\fi{}0.14\ifmmode\pm\else\textpm\fi{}0.50)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, where the uncertainties are statistical, systematic, and the uncertainty on the ${\mathit{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ branching fraction, respectively. We determine an upper limit of $1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ at 90% C.L. for the product branching fraction $\mathcal{B}({\overline{B}}^{0}\ensuremath{\rightarrow}{\mathit{\ensuremath{\Sigma}}}_{c}^{+}(2455)\overline{p})\ifmmode\times\else\texttimes\fi{}\mathcal{B}({\mathit{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})$. Furthermore, we observe an enhancement at the threshold of the invariant mass of the baryon-antibaryon pair.
DOI: 10.1016/j.nima.2012.10.011
2013
Cited 8 times
Test-beam studies of diamond sensors for SLHC
Abstract Diamond sensors are studied as an alternative to silicon sensors to withstand the high radiation doses that are expected in future upgrades of the pixel detectors for the SLHC. Diamond pixel sensors are intrinsically radiation hard and are considered as a possible solution for the innermost tracker layers close to the interaction point where current silicon sensors cannot cope with the harsh radiation environment.An effort to study possible candidates for the upgrades is undergoing using the Fermilab test-beam facility (FTBF), where diamonds and 3D silicon sensors have been studied. Using a CMS pixel-based telescope built and installed at the FTBF, we are studying charge collection efficiencies for un-irradiated and irradiated devices bump-bonded to the CMS PSI46 pixel readout chip. A description of the test-beam effort and preliminary results on diamond sensors will be presented.
DOI: 10.1103/physrevd.83.051101
2011
Cited 8 times
Measurements of branching fractions, polarizations, and direct<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>-violation asymmetries in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>ρ</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mrow><mml:mo>*</mml:mo><mml:mo>+</mml:mo></mml:mrow…
We present measurements of the branching fractions, longitudinal polarization, and direct CP-violation asymmetries for the decays B+ -> rho0 K*+ and B+ -> f0(980) K*+ with a sample of 467+/-5 million BBbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e^+e^- collider at the SLAC National Accelerator Laboratory. We observe B+ -> rho0 K*+ with a significance of 5.3 sigma and measure the branching fraction Br(B+ -> rho0 K*+) = (4.6+/-1.0+/-0.4) x 10^{-6}, the longitudinal polarization fL = 0.78+/-0.12+/-0.03, and the CP-violation asymmetry ACP = 0.31+/-0.13+/-0.03. We observe B+ -> f0(980) K*+ and measure the branching fraction Br(B+ -> f0(980) K*+) x Br(f0(980) -> pi+pi-) = (4.2+/-0.6+/-0.3) x 10^{-6} and the CP-violation asymmetry ACP = -0.15+/-0.12+/-0.03. The first uncertainty quoted is statistical and the second is systematic.
DOI: 10.1103/physrevd.95.092005
2017
Cited 7 times
Measurement of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msubsup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msubsup><mml:msup><mml:mrow…
The processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{0}$ and ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}\ensuremath{\eta}$ are studied over a continuum of energies from threshold to 4 GeV with the initial-state photon radiation method. Using $454\text{ }\text{ }{\text{fb}}^{\ensuremath{-}1}$ of data collected with the BABAR detector at the SLAC PEP-II storage ring, the first measurements of the cross sections for these processes are obtained. The intermediate resonance structures from ${K}^{*0}(K\ensuremath{\pi}{)}^{0}$, ${K}^{*}(892{)}^{\ifmmode\pm\else\textpm\fi{}}(K\ensuremath{\pi}{)}^{\ensuremath{\mp}}$, and ${K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\rho}}^{\ensuremath{\mp}}$ are studied. The $J/\ensuremath{\psi}$ is observed in all of these channels, and corresponding branching fractions are measured.
DOI: 10.1103/physrevd.101.112003
2020
Cited 7 times
Search for lepton-flavor-violating decays <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>D</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>X</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>∓</mml:mo></mml:msup></mml:math>
We present a search for seven lepton-flavor-violating neutral charm meson decays of the type D0→X0e±μ∓, where X0 represents a π0, K0S, ¯K*0, ρ0, ϕ, ω, or η meson. The analysis is based on 468 fb−1 of e+e− annihilation data collected at or close to the Υ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signals are observed, and we establish 90% confidence level upper limits on the branching fractions in the range (5.0−22.5)×10−7. The limits are between 1 and 2 orders of magnitude more stringent than previous measurements.Received 21 April 2020Accepted 26 May 2020DOI:https://doi.org/10.1103/PhysRevD.101.112003Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)PropertiesSymmetriesParticles & Fields
DOI: 10.1016/j.nima.2016.06.113
2016
Cited 6 times
Rate dependence, polarization, and light sensitivity of neutron-irradiated scCVD diamond sensors
We study the dependence of the charge-collection-efficiency, or CCE, on the rate of charged particles impinging on neutron-irradiated single-crystal Chemical-Vapor-Deposition (scCVD) diamond sensors. These effects are not observed in un-irradiated high quality scCVD sensors. The rate dependence appears to be associated with the build-up of an electric field opposing the applied charge-collection field in the sensor. We find that exposure of the detector to red or near-IR light reverses this effect on the CCE during operation.
DOI: 10.1103/physrevd.84.011104
2011
Cited 7 times
Study of dipion bottomonium transitions and search for thehb(1P)state
We study inclusive di-pion decays using a sample of 108 x 10^6 Upsilon(3S) events recorded with the BABAR detector. We search for the decay mode Upsilon(3S) --> pi+ pi- h_b(1P) and find no evidence for the bottomonium spin-singlet state h_b(1P) in the invariant mass distribution recoiling against the pi+ pi- system. Assuming the h_b(1P) mass to be 9.900 GeV/c^2, we measure the upper limit on the branching fraction B[Upsilon(3S) --> pi+ pi- h_b(1P)] < 1.2 x 10^{-4}, at 90% confidence level. We also investigate the chi_{bJ}(2P) --> pi+ pi- chi_{bJ}(1P), Upsilon(3S) --> pi+ pi- Upsilon(2S), and Upsilon(2S) --> pi+ pi- Upsilon(1S) di-pion transitions and present an improved measurement of the branching fraction of the Upsilon(3S) --> pi+ pi- Upsilon(2S) decay and of the Upsilon(3S)-Upsilon(2S) mass difference.
DOI: 10.1007/bf01571802
1986
Cited 13 times
Lepton pair production in double tagged two-photon interactions
DOI: 10.1097/ana.0b013e31818acfa4
2009
Cited 7 times
Fructose-1,6-Bisphosphate and Fructose-2,6-Bisphosphate do not Influence Brain Carbohydrate or High-energy Phosphate Metabolism in a Rat Model of Forebrain Ischemia
Phosphorylated fructose compounds have been reported to lessen neuronal injury in in vitro models of hypoxia and in vivo models of ischemia. Although a variety of mechanisms have been proposed to account for this finding, it is unknown if intracellular uptake and incorporation of these compounds into the glycolytic pathway contribute to the benefit. We evaluated phosphorylated fructose administration in an adult rat model of transient, near-complete cerebral ischemia to determine its impact on brain metabolism before, during, and after ischemia. Fifty-four pentobarbital anesthetized rats were randomly assigned to receive IV infusions of either fructose-1,6-bisphosphate, fructose-2,6-bisphosphate, or 0.9% saline. After 2 hours of infusion, 18 rats (6/treatment group) were subjected to brain harvesting before any ischemia, 18 additional rats had brain harvesting at the completion of 10 minutes of forebrain ischemia (2-vessel occlusion plus induced hypotension), and 18 rats had harvesting after ischemia and 15 minutes of reperfusion. Cortical brain samples were analyzed for ATP, ADP, AMP, phosphocreatine, glucose, and glycogen. When compared with placebo, neither phosphorylated fructose compound altered preischemic, intraischemic, or postischemic concentrations of brain high-energy phosphates, glucose, glycogen, or lactate, nor did they influence the intraischemic metabolism of endogenous brain glucose or glycogen. On the basis of these results, we conclude that mechanisms other than augmented carbohydrate metabolism are responsible for previous reports of neuronal protection by the bisphosphonates.