A. Rýd

Using the CLEO II detector, we have measured the differential cross sections for exclusive two-photon production of light pseudoscalar mesons ${\ensuremath{\pi}}^{0},$ \ensuremath{\eta}, and ${\ensuremath{\eta}}^{\ensuremath{'}}.$ From our measurements we have obtained the form factors associated with the electromagnetic transitions ${\ensuremath{\gamma}}^{*}\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}\mathrm{meson}.$ We have measured these form factors in the momentum transfer ranges from 1.5 to 9, 20, and $30{\mathrm{GeV}}^{2}$ for ${\ensuremath{\pi}}^{0},$ \ensuremath{\eta}, and ${\ensuremath{\eta}}^{\ensuremath{'}},$ respectively, and have made comparisons to various theoretical predictions.

Using data collected with the CLEO detector operating at the CESR e+e- collider at sqrt[s]=3.97-4.26 GeV, we investigate 15 charmonium decay modes of the psi(4040), psi(4160), and Y(4260) resonances. We confirm, at 11 sigma significance, the BABAR Y(4260)-->pi+pi- J/psi discovery, make the first observation of Y(4260)--> pi(0)pi(0) J/psi (5.1 sigma), and find the first evidence for Y(4260)-->K+K- J/psi(3.7 sigma). We measure e+e- cross sections at sqrt[s]=4.26 GeV as sigma(pi+pi- J/psi)=58(+12)(-10)+/-4 pb, sigma(pi(0)pi(0) J/psi)=23(+12)(-8)+/-1 pb, and sigma(K+K- J/psi)=9(+9)(-5)+/-1 pb, in which the uncertainties are statistical and systematic, respectively. Upper limits are placed on other decay rates from all three resonances.

Using $13.3\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collision data taken in the $\ensuremath{\Upsilon}(1S\ensuremath{-}4S)$ region with the CLEO III detector at the CESR collider, a search has been made for the new resonance $Y(4260)$ recently reported by the BABAR Collaboration. The production of $Y(4260)$ in initial state radiation (ISR), and its decay into ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$, are confirmed. A good quality fit to our data is obtained with a single resonance. We determine $M(Y(4260))=({4284}_{\ensuremath{-}16}^{+17}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}4(\mathrm{syst}))\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, $\ensuremath{\Gamma}(Y(4260))=({73}_{\ensuremath{-}25}^{+39}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}5(\mathrm{syst}))\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, and ${\ensuremath{\Gamma}}_{ee}(Y(4260))\ifmmode\times\else\texttimes\fi{}\mathcal{B}(Y(4260)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi})=({8.9}_{\ensuremath{-}3.1}^{+3.9}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.8(\mathrm{syst}))\text{ }\text{ }\mathrm{eV}/{c}^{2}$.

Using $281\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collisions recorded at the $\ensuremath{\psi}(3770)$ resonance with the CLEO-c detector at CESR (Cornell Electron Storage Ring), we determine absolute hadronic branching fractions of charged and neutral $D$ mesons using a double tag technique. Among measurements for three ${D}^{0}$ and six ${D}^{+}$ modes, we obtain reference branching fractions $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})=(3.891\ifmmode\pm\else\textpm\fi{}0.035\ifmmode\pm\else\textpm\fi{}0.059\ifmmode\pm\else\textpm\fi{}0.035)%$ and $\mathcal{B}({D}^{+}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+})=(9.14\ifmmode\pm\else\textpm\fi{}0.10\ifmmode\pm\else\textpm\fi{}0.16\ifmmode\pm\else\textpm\fi{}0.07)%$, where the first uncertainty is statistical, the second is all systematic errors other than final-state radiation (FSR), and the third is the systematic uncertainty due to FSR. We include FSR in these branching fractions by allowing for additional unobserved photons in the final state. Using an independent determination of the integrated luminosity, we also extract the cross sections $\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{0}{\overline{D}}^{0})=(3.66\ifmmode\pm\else\textpm\fi{}0.03\ifmmode\pm\else\textpm\fi{}0.06)\text{ }\text{ }\mathrm{nb}$ and $\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{+}{D}^{\ensuremath{-}})=(2.91\ifmmode\pm\else\textpm\fi{}0.03\ifmmode\pm\else\textpm\fi{}0.05)\text{ }\text{ }\mathrm{nb}$ at a center-of-mass energy, ${E}_{\mathrm{cm}}=3774\ifmmode\pm\else\textpm\fi{}1\text{ }\text{ }\mathrm{MeV}$.

We extract a relatively precise value for the decay constant of the ${D}^{+}$ meson by measuring $\mathcal{B}({D}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}\ensuremath{\nu})=(4.40\ifmmode\pm\else\textpm\fi{}{0.66}_{\ensuremath{-}0.12}^{+0.09})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ using $281\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of data taken on the $\ensuremath{\psi}(3770)$ resonance with the CLEO-$c$ detector. We find ${f}_{{D}^{+}}=(222.6\ifmmode\pm\else\textpm\fi{}{16.7}_{\ensuremath{-}3.4}^{+2.8})\text{ }\text{ }\mathrm{MeV}$, and compare with current theoretical calculations. We also set a 90% confidence upper limit on $\mathcal{B}({D}^{+}\ensuremath{\rightarrow}{e}^{+}\ensuremath{\nu})<2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ which constrains new physics models.

Using the entire CLEO-c ψ(3770)→DD¯ event sample, corresponding to an integrated luminosity of 818 pb−1 and approximately 5.4×106 DD¯ events, we present a study of the decays D0→π−e+νe, D0→K−e+νe, D+→π0e+νe, and D+→K¯0e+νe. Via a tagged analysis technique, in which one D is fully reconstructed in a hadronic mode, partial rates for semileptonic decays by the other D are measured in several q2 bins. We fit these rates using several form factor parametrizations and report the results, including form factor shape parameters and the branching fractions B(D0→π−e+νe)=(0.288±0.008±0.003)%, B(D0→K−e+νe)=(3.50±0.03±0.04)%, B(D+→π0e+νe)=(0.405±0.016±0.009)%, and B(D+→K¯0e+νe)=(8.83±0.10±0.20)%, where the first uncertainties are statistical and the second are systematic. Taking input from lattice quantum chromodynamics, we also find |Vcd|=0.234±0.007±0.002±0.025 and |Vcs|=0.985±0.009±0.006±0.103, where the third uncertainties are from lattice quantum chromodynamics.4 MoreReceived 16 June 2009DOI:https://doi.org/10.1103/PhysRevD.80.032005©2009 American Physical Society

Using the CLEO-c detector at the Cornell Electron Storage Ring, we have measured inclusive and exclusive cross sections for the production of D+, D0 and Ds+ mesons in e+e- annihilations at thirteen center-of-mass energies between 3.97 and 4.26 GeV. Exclusive cross sections are presented for final states consisting of two charm mesons (DD, D*D, D*D*, Ds+Ds-, Ds*+Ds-, and Ds*+Ds*-) and for processes in which the charm-meson pair is accompanied by a pion. No enhancement in any final state is observed at the energy of the Y(4260).

We report the first determination of the relative strong-phase difference between ${D}^{0}\ensuremath{\rightarrow}{K}_{S,L}^{0}{K}^{+}{K}^{\ensuremath{-}}$ and ${\overline{D}}^{0}\ensuremath{\rightarrow}{K}_{S,L}^{0}{K}^{+}{K}^{\ensuremath{-}}$. In addition, we present updated measurements of the relative strong-phase difference between ${D}^{0}\ensuremath{\rightarrow}{K}_{S,L}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\overline{D}}^{0}\ensuremath{\rightarrow}{K}_{S,L}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$. Both measurements exploit the quantum coherence between a pair of ${D}^{0}$ and ${\overline{D}}^{0}$ mesons produced from $\ensuremath{\psi}(3770)$ decays. The strong-phase differences measured are important for determining the Cabibbo-Kobayashi-Maskawa angle $\ensuremath{\gamma}/{\ensuremath{\phi}}_{3}$ in ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\stackrel{\texttildelow{}}{D}}^{0}$ decays, where ${\stackrel{\texttildelow{}}{D}}^{0}$ is a ${D}^{0}$ or ${\overline{D}}^{0}$ meson decaying to ${K}_{S}^{0}{h}^{+}{h}^{\ensuremath{-}}$ ($h=\ensuremath{\pi}$, $K$), in a manner independent of the model assumed to describe the ${D}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}{h}^{+}{h}^{\ensuremath{-}}$ decay. Using our results, the uncertainty in $\ensuremath{\gamma}/{\ensuremath{\phi}}_{3}$ due to the error on the strong-phase difference is expected to be between 1.7\ifmmode^\circ\else\textdegree\fi{} and 3.9\ifmmode^\circ\else\textdegree\fi{} for an analysis using ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\stackrel{\texttildelow{}}{D}}^{0}$, ${\stackrel{\texttildelow{}}{D}}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ decays, and between 3.2\ifmmode^\circ\else\textdegree\fi{} and 3.9\ifmmode^\circ\else\textdegree\fi{} for an analysis based on ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\stackrel{\texttildelow{}}{D}}^{0}$, ${\stackrel{\texttildelow{}}{D}}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{+}{K}^{\ensuremath{-}}$ decays. A measurement is also presented of the $CP$-odd fraction, ${\mathcal{F}}_{\ensuremath{-}}$, of the decay ${D}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{+}{K}^{\ensuremath{-}}$ in the region of the $\ensuremath{\phi}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}$ resonance. We find that in a region within $0.01\text{ }\text{ }{\mathrm{GeV}}^{2}/{c}^{4}$ of the nominal $\ensuremath{\phi}$ mass squared ${\mathcal{F}}_{\ensuremath{-}}>0.91$ at the 90% confidence level.

We have searched for two-body charmless hadronic decays of $B$ mesons. Final states include $ππ$, $K π$, and $KK$ with both charged and neutral kaons and pions; $πρ$, $K ρ$, and $K^*π$; and $Kϕ$, $ K^*ϕ$, and $ϕϕ$. The data used in this analysis consist of 2.6~million $B\bar{B}$~pairs produced at the $Υ(4S)$ taken with the CLEO-II detector at the Cornell Electron Storage Ring (CESR). We measure the branching fraction of the sum of $B^0 \rightarrow π^+π^-$ and $B^0 \rightarrow K^+π^-$ to be $(1.8^{+0.6+0.2}_{-0.5-0.3}\pm0.2) \times 10^{-5}$. In addition, we place upper limits on individual branching fractions in the range from $10^{-4}$ to $10^{-6}$.

We study the exclusive semileptonic B meson decays ${\mathit{B}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}${\mathit{D}}^{\mathrm{*}0}$${\mathit{l}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{} and B${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}^{0}$\ensuremath{\rightarrow}${\mathit{D}}^{\mathrm{*}+}$${\mathit{l}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{} using data collected with the CLEO II detector at the Cornell Electron-positron Storage Ring (CESR). We present measurements of the branching fractions scrB(B${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}^{0}$\ensuremath{\rightarrow}${\mathit{D}}^{\mathrm{*}+}$${\mathit{l}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{})= (0.5/${\mathit{f}}_{00}$)[4.49\ifmmode\pm\else\textpm\fi{}0.32(stat.)\ifmmode\pm\else\textpm\fi{}0.39 (syst.)]% and scrB(${\mathit{B}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}${\mathit{D}}^{\mathrm{*}0}$${\mathit{l}}^{\mathrm{\ensuremath{-}}}$(\ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{})= (0.5/${\mathit{f}}_{+\mathrm{\ensuremath{-}}}$)[5.13\ifmmode\pm\else\textpm\fi{}0.54 (stat) \ifmmode\pm\else\textpm\fi{}0.64 (syst)]%, where ${\mathit{f}}_{00}$ and ${\mathit{f}}_{+\mathrm{\ensuremath{-}}}$ are the neutral and charged B meson production fractions at the \ensuremath{\Upsilon}(4S) resonance, respectively. Assuming isospin invariance and taking the ratio of charged to neutral B meson lifetimes measured at higher energy machines, we determine the ratio ${\mathit{f}}_{+\mathrm{\ensuremath{-}}}$/${\mathit{f}}_{00}$=1.04\ifmmode\pm\else\textpm\fi{}0.13 (stat) \ifmmode\pm\else\textpm\fi{}0.12 (syst) \ifmmode\pm\else\textpm\fi{}0.10 (lifetime); further assuming ${\mathit{f}}_{+\mathrm{\ensuremath{-}}}$+${\mathit{f}}_{00}$=1 we also determine the partial width \ensuremath{\Gamma}(B\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\rightarrow}${\mathit{D}}^{\mathrm{*}}$l\ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{})=[29.9\ifmmode\pm\else\textpm\fi{}1.9 (stat) \ifmmode\pm\else\textpm\fi{}2.7 (syst.) \ifmmode\pm\else\textpm\fi{}2.0 (lifetime)] ${\mathrm{ns}}^{\mathrm{\ensuremath{-}}1}$ (independent of ${\mathit{f}}_{+\mathrm{\ensuremath{-}}}$/${\mathit{f}}_{00}$).From this partial width we calculate B\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\rightarrow}${\mathit{D}}^{\mathrm{*}}$l\ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{} branching fractions that do not depend on ${\mathit{f}}_{+\mathrm{\ensuremath{-}}}$/${\mathit{f}}_{00}$ or the individual B lifetimes, but only on the charged to neutral B lifetime ratio. The product of the CKM matrix element \ensuremath{\Vert}${\mathit{V}}_{\mathit{c}\mathit{b}}$\ensuremath{\Vert} times the normalization of the decay form factor at the point of no recoil of the ${\mathit{D}}^{\mathrm{*}}$ meson, scrF(y=1), is determined from a linear fit to the combined differential decay rate of the exclusive B\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\rightarrow}${\mathit{D}}^{\mathrm{*}}$l\ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{} decays: \ensuremath{\Vert}${\mathit{V}}_{\mathit{c}\mathit{b}}$\ensuremath{\Vert}scrF(1)=0.0351\ifmmode\pm\else\textpm\fi{}0.0019 (stat) \ifmmode\pm\else\textpm\fi{}0.0018 (syst) \ifmmode\pm\else\textpm\fi{}0.0008 (lifetime). The value for \ensuremath{\Vert}${\mathit{V}}_{\mathit{c}\mathit{b}}$\ensuremath{\Vert} is extracted using theoretical calculations of the form factor normalization.

We have studied the "wrong-sign" process D0-->K+pi(-) to search for D0-&Dmacr;( 0) mixing. The data come from 9.0 fb(-1) of e(+)e(-) collisions at sqrt[s] approximately 10 GeV recorded with the CLEO II. V detector. We measure the relative rate of the wrong-sign process D0-->K+pi(-) to the Cabibbo-favored process &Dmacr;( 0)-->K+pi(-) to be R = (0.332(+0.063)(-0.065)+/-0.040)%. We study D0-->K+pi(-) as a function of decay time to distinguish direct doubly Cabibbo-suppressed decay from D0-&Dmacr;( 0) mixing. The amplitudes that describe D0-&Dmacr;( 0) mixing, x(') and y('), are consistent with zero. At the 95% C.L. and without assumptions concerning charge-parity ( CP) violating parameters, we find (1/2)x('2)<0.041% and -5.8%<y(')<1.0%.

The h(c)((1)P(1)) state of charmonium has been observed in the reaction psi(2S) --> pi(0)h(c) --> (gammagamma)(gammaeta(c)) using 3.08 x10(6) psi(2S) decays recorded in the CLEO detector. Data have been analyzed both for the inclusive reaction, where the decay products of the eta(c) are not identified, and for exclusive reactions, in which eta(c) decays are reconstructed in seven hadronic decay channels. We find M(h(c)) = 3524.4 +/- 0.6 +/- 0.4 MeV which corresponds to a hyperfine splitting DeltaM(hf)(1P) triple-bond <M((3)P(J)) - M((1)P(1)) = +1.0 +/- 0.6 +/- 0.4 MeV, and B(psi(2S) --> pi(0)h(c)) x B(h(c) --> gammaeta(c)) = (4.0 +/- 0.8 +/- 0.7) x 10(-4).

Using the CLEO II detector and a sample of 955 000 Υ(4S) decays we have confirmed charmless semileptonic decays of B mesons. In the momentum interval 2.3–2.6 GeV/c we observe an excess of 107±15±11 leptons, which we attribute to b→ulν. This result yields a model-dependent range of values for ‖Vub/Vcb‖ that is lower than has been obtained in previous studies. For the inclusive spectator model of Altarelli et al. we find ‖Vub/Vcb‖=0.076±0.008. Models that describe b→ulν with a limited set of exclusive final states give ‖Vub/Vcb‖=0.06-0.10.Received 7 September 1993DOI:https://doi.org/10.1103/PhysRevLett.71.4111©1993 American Physical Society

Using $55.8\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collisions recorded at the $\ensuremath{\psi}(3770)$ resonance with the CLEO-c detector at CESR, we determine absolute hadronic branching fractions of charged and neutral $D$ mesons using a double tag technique. Among measurements for three ${D}^{0}$ and six ${D}^{+}$ modes, we obtain reference branching fractions $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})=(3.91\ifmmode\pm\else\textpm\fi{}0.08\ifmmode\pm\else\textpm\fi{}0.09)%$ and $\mathcal{B}({D}^{+}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+})=(9.5\ifmmode\pm\else\textpm\fi{}0.2\ifmmode\pm\else\textpm\fi{}0.3)%$, where the uncertainties are statistical and systematic, respectively. Final state radiation is included in these branching fractions by allowing for additional, unobserved, photons in the final state. Using a determination of the integrated luminosity, we also extract the cross sections $\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{0}{\overline{D}}^{0})=(3.60\ifmmode\pm\else\textpm\fi{}{0.07}_{\ensuremath{-}0.05}^{+0.07})\text{ }\text{ }\mathrm{nb}$ and $\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{+}{D}^{\ensuremath{-}})=(2.79\ifmmode\pm\else\textpm\fi{}{0.07}_{\ensuremath{-}0.04}^{+0.10})\text{ }\text{ }\mathrm{nb}$.

We search for a non-SM-like CP-odd Higgs boson (a(1)(0)) decaying to tau(+)tau(-) or mu(+)mu(-) in radiative decays of the Upsilon(1S). No significant signal is found, and upper limits on the product branching ratios are set. Our tau(+)tau(-) results are almost 2 orders of magnitude more stringent than previous upper limits. Our data provide no evidence for a Higgs state with a mass of 214 MeV decaying to mu(+)mu(-), previously proposed as an explanation for 3 Sigma(+)-->pmu(+)mu(-) events observed by the HyperCP experiment. Our results constrain NMSSM models.

The decays of $\ensuremath{\psi}(2S)$ into $\ensuremath{\gamma}p\overline{p}$, ${\ensuremath{\pi}}^{0}p\overline{p}$, and $\ensuremath{\eta}p\overline{p}$ have been studied with the CLEO-c detector using a sample of $24.5\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\psi}(2S)$ events obtained from ${e}^{+}{e}^{\ensuremath{-}}$ annihilations at $\sqrt{s}=3686\text{ }\text{ }\mathrm{MeV}$. The data show evidence for the excitation of several ${N}^{*}$ resonances in $p{\ensuremath{\pi}}^{0}$ and $p\ensuremath{\eta}$ channels in ${\ensuremath{\pi}}^{0}p\overline{p}$ and $\ensuremath{\eta}p\overline{p}$ decays, and ${f}_{2}$ states in $\ensuremath{\gamma}p\overline{p}$ decay. Branching fractions for decays of $\ensuremath{\psi}(2S)$ to $\ensuremath{\gamma}p\overline{p}$, ${\ensuremath{\pi}}^{0}p\overline{p}$, and $\ensuremath{\eta}p\overline{p}$ have been determined. No evidence for $p\overline{p}$ threshold enhancements was found in the reactions $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}Xp\overline{p}$, where $X=\ensuremath{\gamma}$, ${\ensuremath{\pi}}^{0}$, $\ensuremath{\eta}$. We do, however, find confirming evidence for a $p\overline{p}$ threshold enhancement in $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}p\overline{p}$ as previously reported by BES.

Using $2.45\ifmmode\times\else\texttimes\fi{}{10}^{7}$ $\ensuremath{\psi}(2S)$ decays collected with the CLEO-c detector at the Cornell Electron Storage Ring we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure $\mathcal{B}\mathbf{(}\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c}\mathbf{)}=(4.32\ifmmode\pm\else\textpm\fi{}0.16\ifmmode\pm\else\textpm\fi{}0.60)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, $\mathcal{B}(J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c})/\mathcal{B}\mathbf{(}\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c}\mathbf{)}=4.59\ifmmode\pm\else\textpm\fi{}0.23\ifmmode\pm\else\textpm\fi{}0.64$, and $\mathcal{B}(J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c})=(1.98\ifmmode\pm\else\textpm\fi{}0.09\ifmmode\pm\else\textpm\fi{}0.30)%$. We observe a distortion in the ${\ensuremath{\eta}}_{c}$ line shape due to the photon-energy dependence of the magnetic dipole transition rate. We find that measurements of the ${\ensuremath{\eta}}_{c}$ mass are sensitive to the line shape, suggesting an explanation for the discrepancy between measurements of the ${\ensuremath{\eta}}_{c}$ mass in radiative transitions and other production mechanisms.

Using e+e−→D−sD*+s and D*−sD+s interactions at 4170 MeV collected with the CLEO-c detector, we investigate the semileptonic decays D+s→f0(980)e+ν and D+s→ϕe+ν. By examining the decay rates as functions of the four-momentum transfer squared q2, we measure the ratio [dBdq2(D+s→f0(980)e+ν)B(f0→π+π−)]/[dBdq2(D+s→ϕe+ν)B(ϕ→K+K−)] at q2 of zero to be (42±11)%. This ratio has been predicted to equal the rate ratio [B(Bs→J/ψf0)B(f0→π+π−)]/[B(Bs→J/ψϕ)B(ϕ→K+K−)], thus indicating that the CP eigenstate J/ψf0 could be useful for measuring CP violation via Bs mixing. Assuming a simple pole model for the form factor |f+(q2)| in the f0e+ν decay, we find a pole mass of (1.7+4.5−0.7±0.2) GeV. We also determine the f0 mass and width as (977+11−9±1) and (91+30−22±3) MeV, respectively. In addition, we present updated results for B(D+s→f0(980)e+ν)B(f0→π+π−)=(0.20±0.03±0.01)% and B(D+s→ϕe+ν)=(2.36±0.23±0.13)%. Assuming that the f0 wave function is a combination of strange and nonstrange quark-antiquark components, we use our measurement for B(D+s→f0(980)e+ν) to extract a value of the mixing angle that we find consistent with ∣¯ss⟩ dominance, adding to the mystery as to why the f0 decays predominantly to two pions rather than two kaons.2 MoreReceived 18 July 2009DOI:https://doi.org/10.1103/PhysRevD.80.052009©2009 American Physical Society

We examine e + e -→ D - s D * + s and D * - s D + s interactions at 4170 MeV using the CLEO-c detector in order to measure the decay constant f D + s with good precision.Previously our measurements were substantially higher than the most precise lattice based QCD calculation of (241±3) MeV.Here we use the D + s → ℓ + ν channel, where the ℓ + designates either a µ + or a τ + , when the τ + → π + ν.Analyzing both modes independently, we determine B(D + s → µ + ν) = (0.565± 0.045± 0.017)%, and B(D + s → τ + ν) = (6.42± 0.81 ± 0.18)%.We also analyze them simultaneously to find an effective value of B eff (D + s → µ + ν) = (0.591±0.037±0.018)%and f D + s = (263.3±8.2±3.9)MeV.Combining with the CLEO-c value determined independently using D + s → τ + ν, τ + → e + ν ν decays, we extract f D + s = (259.5 ± 6.6 ± 3.1) MeV.Combining with our previous determination of B(D + → µ + ν), we extract the ratio f D + s /f D + = 1.26 ± 0.06 ± 0.02.No evidence is found for a CP asymmetry between Γ(D + s → µ + ν) and Γ(D - s → µ -ν); specifically the fractional difference in rates is measured to be (4.8±6.1)%.Finally, we find B(D + s → e + ν) < 1.2 × 10 -4 at 90% confidence level.

We report evidence for the ground state of bottomonium, eta_b(1S), in the radiative decay Upsilon(3S) --> gamma eta_b in e^+e^- annihilation data taken with the CLEO III detector. Using 6 million Upsilon(3S) decays, and assuming Gamma(eta_b) = 10 MeV/c^2, we obtain B(Upsilon(3S) --> gamma eta_b) = (7.1 +- 1.8 +- 1.1) X 10^{-4}, where the first error is statistical and the second is systematic. The statistical significance is about 4 sigma. The mass is determined to be M(eta_b) = 9391.8 +- 6.6 +- 2.0 MeV/c^2, which corresponds to the hyperfine splitting Delta M_{hf}(1S)_b = 68.5 +- 6.6 +- 2.0 MeV/c^2. Using 9 million Upsilon(2S) decays, we place an upper limit on the corresponding Y(2S) decay, B(Y(2S) --> gamma eta_b) < 8.4 X 10^{-4} at 90 % confidence level.

We perform a Dalitz plot analysis of about 100,000 Ds+ decays to K+ K- pi+ and measure the complex amplitudes of the intermediate resonances which contribute to this decay mode. We also measure the relative branching fractions of Ds+ --> K+ K+ pi- and Ds+ --> K+ K+ K-. For this analysis we use a 384 fb-1 data sample, recorded by the BABAR detector at the PEP-II asymmetric-energy e+e- collider running at center-of-mass energies near 10.58 GeV.

We have used the CLEO II detector and $2.06{\mathrm{fb}}^{\ensuremath{-}1}$ of $\ensuremath{\Upsilon}(4S)$ data to measure the $B$-meson semileptonic branching fraction. The $B\ensuremath{\rightarrow}\mathrm{Xe}\ensuremath{\nu}$ momentum spectrum was obtained over nearly the full momentum range by using charge and kinematic correlations in events with a high-momentum lepton tag and an additional electron. We find $B(B\ensuremath{\rightarrow}\mathrm{Xe}\ensuremath{\nu})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(10.49\ifmmode\pm\else\textpm\fi{}0.17\ifmmode\pm\else\textpm\fi{}0.43)%$, with overall systematic uncertainties less than those of untagged single-lepton measurements. We use this result to calculate the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element ${V}_{\mathrm{cb}}$ and to set an upper limit on the fraction of $\ensuremath{\Upsilon}(4S)$ decays to final states other than $B\overline{B}$.

Using a sample of $2.6\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\Upsilon}(4\mathrm{S})\ensuremath{\rightarrow}B\overline{B}$ events collected with the CLEO II detector at the Cornell Electron Storage Ring, we have measured the form factors for ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{*+}{\ensuremath{\ell}}^{\ensuremath{-}}\overline{\ensuremath{\nu}}$. We perform a three-parameter fit with the joint distribution of four kinematic variables to obtain the form-factor ratios ${R}_{1}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.18\ifmmode\pm\else\textpm\fi{}0.30\ifmmode\pm\else\textpm\fi{}0.12$ and ${R}_{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.71\ifmmode\pm\else\textpm\fi{}0.22\ifmmode\pm\else\textpm\fi{}0.07,$ and the form-factor slope ${\ensuremath{\rho}}_{{A}_{1}}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.91\ifmmode\pm\else\textpm\fi{}0.15\ifmmode\pm\else\textpm\fi{}0.06,$ which is closely related to the slope of the Isgur-Wise function. The form-factor ratios are consistent with predicted corrections to the heavy-quark symmetry limit ${R}_{1}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}R}_{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$.

We propose a way of measuring the photon polarization in radiative B decays into K resonance states decaying to Kpipi, which can test the standard model and probe new physics. The photon polarization is shown to be measured by the up-down asymmetry of the photon direction relative to the Kpipi decay plane in the K resonance rest frame. The integrated asymmetry in K1(1400)-->Kpipi, calculated to be 0.34 plus/minus 0.05 in the standard model, is measurable at currently operating B factories.

We have measured the B0B¯0 mixing probability, χd, using a sample of 965 000 BB¯ pairs from Υ(4S) decays. Counting dilepton events, we find χd=0.157±0.016±0.018−0.021+0.028. Using tagged B0 events, we find χd=0.149±0.023±0.019±0.010. The first (second) error is statistical (systematic). The third error reflects a ±15% uncertainty in the assumption, made in both cases, that charged and neutral B pairs contribute equally to dilepton events. We also obtain a limit on the CP impurity in the Bd0 system, ‖Re(εB0)‖<0.045 at 90% C.L.Received 29 April 1993DOI:https://doi.org/10.1103/PhysRevLett.71.1680©1993 American Physical Society

We present measurements of spectral moments extracted from the invariant mass distributions of the final states of hadronic τ decay products recorded in the CLEO detector. From a fit of theoretical predictions to the measurements of spectral moments and the total hadronic decay width of the τ, we determine the strong coupling constant and a set of non-perturbative QCD parameters. The strong coupling constant is measured to be αs(mτ) = 0.306 ± 0.024, which when extrapolated to the Z mass, yields αs(Mz) = 0.114 ± 0.003.

We observe signals for the decays ψ(3770)→XJ/ψ from data acquired with the CLEO detector operating at the CESR e+e− collider with √s=3773 MeV. We measure the following branching fractions B(ψ(3770)→XJ/ψ) and significances: (189±20±20)×10−5 (11.6σ) for X=π+π−, (80±25±16)×10−5 (3.4σ) for X=π0π0, and (87±33±22)×10−5 (3.5σ) for X=η, where the errors are statistical and systematic, respectively. The radiative return process e+e−→γψ(2S) populates the same event sample and is used to measure Γee[ψ(2S)]=(2.54±0.03±0.11) keV.Received 9 August 2005DOI:https://doi.org/10.1103/PhysRevLett.96.082004©2006 American Physical Society

The resonant substructure in D0 --> K0S pi+ pi- decays is described by a combination of ten quasi two-body intermediate states which include both CP-even and CP-odd eigenstates and one doubly-Cabibbo suppressed channel. We present a formalism that connects the variation in D0 decay time over the Dalitz plot with the mixing parameters, x and y, that describe off-shell and on-shell D0-D0B mixing. We analyze the CLEO II.V data sample and find the parameters x and y are consistent with zero. We limit (-4.7 < x < 8.6)% and (-6.1 < y < 3.5)% at the 95\% confidence level

A precision measurement of the mass of the h_c(1P1) state of charmonium has been made using a sample of 24.5 million psi(2S) events produced in e+e- annihilation at CESR. The reaction used was psi(2S) -> pi0 h_c, pi0 -> gamma gamma, h_c -> gamma eta_c, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which eta_c decays are reconstructed in fifteen hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(h_c)=3525.28+-0.19 (stat)+-0.12(syst) MeV, and B(psi(2S) -> pi0 h_c)xB(h_c -> gamma eta_c)= (4.19+-0.32+-0.45)x10^-4. Using the 3PJ centroid mass, Delta M_hf(1P)=<M(chi_cJ)> - M(h_c) = +0.02+-0.19+-0.13 MeV.

Analyzing 600/pb of e+e- collisions at 4170 MeV center-of-mass energy with the CLEO-c detector, we measure the branching fraction B(Ds+ -> tau+ nu)=(5.52\pm 0.57\pm 0.21)% using the tau+ -> rho^+ anti-nu decay mode. Combining with other CLEO measurements of B(Ds+ -> tau+ nu) we determine the pseudoscalar decay constant fDs = (259.7\pm 7.8\pm 3.4) MeV consistent with the value obtained from our Ds+ -> mu+ nu measurement of (257.6\pm 10.3\pm 4.3) MeV. Combining these measurements we find a value of fDs=(259.0 \pm 6.2\pm 3.0) MeV, that differs from the most accurate prediction based on unquenched lattice gauge theory of (241\pm 3) MeV by 2.4 standard deviations. We also present the first measurements of B(Ds+ -> K0 pi+ pi0)=(1.00\pm0.18\pm 0.04)%, and B(Ds+ -> pi+ pi0 pi0)=(0.65\pm0.13\pm 0.03)%, and measure a new value for B(Ds+ -> eta rho+)=(8.9\pm0.6\pm0.5)%.

Using data collected on the ψ(3770) resonance and near the D*±sD∓s peak production energy by the CLEO-c detector, we study the decays of the possible D→PP modes and report measurements of or upper limits on all branching fractions for Cabibbo-favored, singly Cabibbo-suppressed, and doubly Cabibbo-suppressed D→PP decays except modes involving K0L (and except D0→K+π−). We normalize with respect to the Cabibbo-favored D modes, D0→K−π+, D+→K−π+π+, and D+s→K+K0S.Received 17 June 2009DOI:https://doi.org/10.1103/PhysRevD.81.052013©2010 American Physical Society

Using 586 pb(-1) of e+ e- collision data at E(c.m.) = 4170 MeV, produced at the Cornell Electron Storage Ring collider and collected with the CLEO-c detector, we observe the process e+ e- → π+ π- h(c)(1P). We measure its cross section to be 15.6±2.3±1.9±3.0 pb, where the third error is due to the external uncertainty on the branching fraction of ψ(2S) → π0 h(c)(1P), which we use for normalization. We also find evidence for e+ e- → ηh(c)(1P) at 4170 MeV at the 3σ level and see hints of a rise in the e+ e- → π+ π- h(c)(1P) cross section at 4260 MeV.

The branching fractions of ${D}_{s}^{\ifmmode\pm\else\textpm\fi{}}$ meson decays serve to normalize many measurements of processes involving charm quarks. Using $586\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for 13 ${D}_{s}^{\ifmmode\pm\else\textpm\fi{}}$ decays in 16 reconstructed final states with a double tag technique. In particular we make a precise measurement of the branching fraction $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{K}^{+}{\ensuremath{\pi}}^{+})=(5.55\ifmmode\pm\else\textpm\fi{}0.14\ifmmode\pm\else\textpm\fi{}0.13)%$, where the uncertainties are statistical and systematic, respectively. We find a significantly reduced value of $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}{\ensuremath{\eta}}^{\ensuremath{'}})$ compared to the world average, and our results bring the inclusively and exclusively measured values of $\mathcal{B}({D}_{s}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}X)$ into agreement. We also search for $CP$-violating asymmetries in ${D}_{s}$ decays and measure the cross section of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}_{s}^{*}{D}_{s}$ at ${E}_{\mathrm{cm}}=4.17\text{ }\text{ }\mathrm{GeV}$.

We have studied two-body charmless hadronic decays of B mesons into the final states $\pi\pi$, $K \pi$, and $KK$. Using 3.3 million $B\bar{B}$ pairs collected with the CLEO-II detector, we have made the first observation of the decays $B^0\to K^+\pi^-$, $B^+\to K^0\pi^+$, and the sum of $B^+ \to \pi^+\pi^0$ and $B^+ \to K^+\pi^0$ decays (an average over charge-conjugate states is always implied). We place upper limits on branching fractions for the remaining decay modes.

We describe a search for psi(3770) decay to two-body non-DDbar final states in e+e- data produced by the CESR collider and analyzed with the CLEO-c detector. Vector-pseudoscalar production of Rho0Pi0, Rho+Pi-, OmegaPi0, PhiPi0, RhoEta, OmegaEta, PhiEta, RhoEtaPrime, OmegaEtaPrime, PhiEtaPrime, Kstar0 K0bar, and Kstar+K- is studied along with that of BOnePi (BOne0Pi0 and BOne+Pi-) and Pi+Pi-Pi0. A statistically significant signal is found for PhiEta, at an excess cross section of (2.4 +- 0.6) pb [Gamma_{PhiEta} (psi(3770)) =(74 +- 16)Mev], and a suggestive suppression of Pi+Pi-Pi0 and RhoPi. We conclude with form factor determinations for OmegaPi0, RhoEta, and RhoEtaPrime.

Using a sample of integrated luminosity 1.68 fb−1 collected with the CLEO-II detector at the Cornell Electron Storage Ring, we measure the branching ratios for the dominant exclusive semileptonic decays D → Klν and D → K∗lν, using charged and neutral D mesons. We also make a precise measurement of the vector form factor for the decay D0 → K−l+ν, using a sample of 2700 events.

We perform a Dalitz plot analysis of D^+ -> K^-pi^+pi^+ decay with the CLEO-c data set of 572 pb^-1 of e^+e^- collisions accumulated at the psi(3770). This corresponds to 1.6 million D^+D^- pairs from which we select 140793 candidate events with a small background of 1.1%. We compare our results with previous measurements using the isobar model. We modify the isobar model with improved description of some of the contributing resonances, and get better agreement with our data. We also consider a quasi-model-independent approach and measure the magnitude and phase of the contributing K pi S wave in the range of invariant masses from the threshold to the maximum in this decay. This gives an improved descriptions of our data over the isobar model. Finally we allow for an isospin-two pi^+pi^+ S-wave contribution, and find that adding this to both the isobar model and quasi-model-independent approach gives the best description of our data.

From e+e- collision data acquired with the CLEO-c detector at CESR, we search for the non-DDbar decays psi(3770) -> gamma chi_cJ, with chi_cJ reconstructed in four exclusive decays modes containing charged pions and kaons. We report the first observation of such decays for J=0 with a branching ratio of (0.73+-0.07+-0.06)%. The rates for different J are consistent with the expectations assuming psi(3770) is predominantly a 1^3D_1 state of charmonium, but only if relativistic corrections are applied.

We study semileptonic B decay to the exclusive charmless states pi, rho/omega, eta, and eta;{'} using the 16 fb(-1) CLEO Upsilon(4S) data sample. We find B(B0-->pi-l+nu)=(1.37+/-0.15stat+/-0.11sys)x10(-4) and B(B0-->rho-l+nu)=(2.93+/-0.37stat+/-0.37sys)x10(-4) and find evidence for B+-->eta'l+nu, with B(B+-->eta'l+nu)=(2.66+/-0.80stat+/-0.56sys)x10(-4). From our B-->pilnu rate for q2>16 GeV2 and lattice QCD, we find |Vub|=(3.6+/0.4stat+/0.2syst-0.4thy+0.6)x10(-3) [corrected]

The branching fractions of D±s meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 pb−1 of e+e− collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D±s decays with a double tag technique. In particular we determine the branching fraction B(D+s→K−K+π+)=(5.50±0.23±0.16)%, where the uncertainties are statistical and systematic, respectively. We also provide partial branching fractions for kinematic subsets of the K−K+π+ decay mode.Received 18 December 2007DOI:https://doi.org/10.1103/PhysRevLett.100.161804©2008 American Physical Society

We have studied the leptonic decay ${D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}{\ensuremath{\nu}}_{\ensuremath{\tau}}$, via the decay channel ${\ensuremath{\tau}}^{+}\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\nu}}_{e}{\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}}$, using a sample of tagged ${D}_{s}^{+}$ decays collected near the ${D}_{s}^{*\ifmmode\pm\else\textpm\fi{}}{D}_{s}^{\ensuremath{\mp}}$ peak production energy in ${e}^{+}{e}^{\ensuremath{-}}$ collisions with the CLEO-c detector. We obtain $\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}{\ensuremath{\nu}}_{\ensuremath{\tau}})=(5.30\ifmmode\pm\else\textpm\fi{}0.47\ifmmode\pm\else\textpm\fi{}0.22)%$ and determine the decay constant ${f}_{{D}_{s}}=(252.5\ifmmode\pm\else\textpm\fi{}11.1\ifmmode\pm\else\textpm\fi{}5.2)\text{ }\text{ }\mathrm{MeV}$, where the first uncertainties are statistical and the second are systematic.

We measure the decay constant f(Ds+) using the D(s+)-->l+ nu channel, where the l+ designates either a mu+ or a tau+, when the tau+ -->pi+ nu. Using both measurements we find f(Ds+)=274+/-13+/-7 MeV. Combining with our previous determination of f(D+), we compute the ratio f(Ds+)/f(D+)=1.23+/-0.11+/-0.04. We compare with theoretical estimates.

We report determination of branching fractions for the decays psi(2S) --> h + J/psi, where h=any, pi+pi-, pi0pi0, eta, pi0, and gamma gamma through chi_{c0,1,2}. These measurements use 27M psi(2S) decays produced in e+e- collision data collected with the CLEO detector. The resulting branching fractions and ratios thereof improve upon previously achieved precision in all cases, and in combination with other measurements permit determination of B(chi_cJ --> gamma J/psi) and B(psi(2S) --> light hadrons).

We exploit the quantum coherence between pair-produced ${D}^{0}$ and ${\overline{D}}^{0}$ in $\ensuremath{\psi}(3770)$ decays to make a first determination of the relative strong phase differences between ${D}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\overline{D}}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, which are of great importance in determining the Cabibbo-Kobayashi-Maskawa angle $\ensuremath{\gamma}/{\ensuremath{\phi}}_{3}$ in ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{0}({\overline{D}}^{0}){K}^{\ensuremath{-}}$ decays. Using $818\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collision data collected with the CLEO-c detector at ${E}_{\mathrm{cm}}=3.77\text{ }\text{ }\mathrm{GeV}$, we employ a binned Dalitz-plot analysis of ${K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${K}_{L}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ decays recoiling against flavor-tagged, $CP$-tagged, and ${K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$-tagged events to determine these strong phase differences.

Using data acquired with the CLEO-c detector at the CESR e+e− collider, we measure branching fractions for J/ψ, ψ(2S), and ψ(3770) decays to γπ0, γη, and γη′. Defining Rn≡B[ψ(nS)→γη]/B[ψ(nS)→γη′], we obtain R1=(21.1±0.9)% and, unexpectedly, an order of magnitude smaller limit, R2<1.8% at 90% C.L. We also use J/ψ→γη′ events to determine branching fractions of improved precision for the five most copious η′ decay modes.Received 8 April 2009DOI:https://doi.org/10.1103/PhysRevD.79.111101©2009 American Physical Society

Utilizing the full CLEO-c data sample of 818 pb -1 of e + e -data taken at the ψ(3770) resonance, we update our measurements of absolute hadronic branching fractions of charged and neutral D mesons.We previously reported results from subsets of these data.Using a double tag technique we obtain branching fractions for three D 0 and six D + modes, including the reference branching fractions B(D 0 → K -π + ) = (3.934± 0.021 ± 0.061)% and B(D + → K -π + π + ) = (9.224± 0.059 ± 0.157)%.The uncertainties are statistical and systematic, respectively.In these measurements we include the effects of final-state radiation by allowing for additional unobserved photons in the final state, and the systematic errors include our estimates of the uncertainties of these effects.Furthermore, using an independent measurement of the luminosity, we obtain the cross sections σ(e + e -→ D 0 D 0 ) = (3.607± 0.017 ± 0.056) nb and σ(e + e -→ D + D -) = (2.882± 0.018 ± 0.042) nb at a center of mass energy, E cm = 3774 ± 1 MeV.

Using data taken with the CLEO II detector at the Cornell Electron Storage Ring, we present the first full angular analysis in the color-suppressed modes B0→J/ψK*0 and B+→J/ψK*+. This leads to a complete determination of the decay amplitudes of these modes including the longitudinal polarization γL/γ=0.52±0.07±0.04 and the P wave component |P|2=0.16±0.08±0.04. In addition, we update the branching fractions for B→J/ψK and B→J/ψK∗.Received 24 February 1997DOI:https://doi.org/10.1103/PhysRevLett.79.4533©1997 American Physical Society

Using data recorded by the CLEO II detector at the Cornell Electron Storage Ring, we report the first observation of an excited charmed baryon decaying into ${\ensuremath{\Xi}}_{c}^{0}{\ensuremath{\pi}}^{+}$. The state has mass difference $M({\ensuremath{\Xi}}_{c}^{0}{\ensuremath{\pi}}^{+})\ensuremath{-}M({\ensuremath{\Xi}}_{c}^{0})$ of $174.3\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}1.0\mathrm{MeV}{/c}^{2}$, and a width of $&lt;3.1\mathrm{MeV}{/c}^{2}$ (90% confidence level limit). We identify the new state as the ${\ensuremath{\Xi}}_{c}^{*+}$, the isospin partner of the recently discovered ${\ensuremath{\Xi}}_{c}^{*0}$.

The decay ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}\ensuremath{\eta}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ has been observed with the CLEO II detector. The $\ensuremath{\eta}$ meson is reconstructed using two decay channels, $\ensuremath{\eta}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$ and ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$. The measured branching fraction is $B({\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}\ensuremath{\eta}{\ensuremath{\nu}}_{\ensuremath{\tau}})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(2.6\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.4)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, somewhat higher than theoretical estimates. An improved upper limit for the second-class-current decay ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\eta}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ is set, $B({\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\eta}{\ensuremath{\nu}}_{\ensuremath{\tau}})&lt;1.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ at 95% C.L., consistent with theoretical expectations.

We have studied the inclusive photon spectra in Upsilon(2S) and Υ(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates and photon energies for Upsilon(2S)-&gt;gamma chi_bJ(1P) and Upsilon(3S)-&gt;gamma chi_bJ(2P) J=0,1,2. We measure the rate for a rare E1 transition Upsilon(3S)-&gt;gamma chi_b0(1P) for the first time. We also set upper limits on the rates for the hindered magnetic dipole (M1) transitions to the eta_b(1S) and eta_b(2S) states.

Using the CLEO II detector, we have measured the branching fractions for $\ensuremath{\Upsilon}(3S)\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi}\ensuremath{\Upsilon}(1S)$, $\ensuremath{\Upsilon}(3S)\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi}\ensuremath{\Upsilon}(2S)$, and the cascade $\ensuremath{\Upsilon}(3S)\ensuremath{\rightarrow}\ensuremath{\Upsilon}(2S)+X$, $\ensuremath{\Upsilon}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(1S)$, analyzing the exclusive mode where the daughter $\ensuremath{\Upsilon}$ state decays to a ${e}^{+}{e}^{\ensuremath{-}}$ or ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ pair, as well as the inclusive ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ transitions where the final $\ensuremath{\Upsilon}$ state decays into hadrons. Properties of the $\ensuremath{\pi}\ensuremath{\pi}$ system are analyzed. Searches for the cascade decay $\ensuremath{\Upsilon}(3S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{h}_{b}$, ${h}_{b}\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{b}$ and $\ensuremath{\Upsilon}(3S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{h}_{b}$ were also performed.

We report results from a search for the decays ${\mathit{B}}^{0}$\ensuremath{\rightarrow}${\mathrm{\ensuremath{\pi}}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$, ${\mathit{B}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$, and ${\mathit{B}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{+}$${\mathit{K}}^{\mathrm{\ensuremath{-}}}$. We find 90% confidence level upper limits on the branching fractions, ${\mathit{B}}_{\mathrm{\ensuremath{\pi}}\mathrm{\ensuremath{\pi}}}$2.9\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$, ${\mathit{B}}_{\mathit{K}\mathrm{\ensuremath{\pi}}}$2.6\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$, and ${\mathit{B}}_{\mathit{K}\mathit{K}}$0.7\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$. While there is no statistically significant signal in the individual modes, the sum of ${\mathit{B}}_{\mathrm{\ensuremath{\pi}}\mathrm{\ensuremath{\pi}}}$ and ${\mathit{B}}_{\mathit{K}\mathrm{\ensuremath{\pi}}}$ exceeds zero with a significance of more than 4 standard deviations, indicating that we have observed charmless hadronic B decays.

We investigate the decays D(0)-->pi(-)l(+)nu and D(0)-->K(-)l(+)nu, where l is e or mu, using approximately 7 fb(-1) of data collected with the CLEO III detector. We find R(0) identical with B(D(0)-->pi(-)e(+)nu)/B(D(0)-->K(-)e(+)nu)=0.082+/-0.006+/-0.005. Fits to the kinematic distributions of the data provide parameters describing the form factor of each mode. Combining the form factor results and R(0) gives |f(pi)(+)(0)|(2)|V(cd)|(2)/|f(K)(+)(0)|(2)|V(cs)|(2)=0.038(+0.006+0.005)(-0.007-0.003).

We exploit the quantum coherence between pair-produced D0 and ¯¯¯D0 in ψ(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase δ between doubly Cabibbo-suppressed D0→K+π− and Cabibbo-favored ¯¯¯D0→K+π−. We analyze a sample of 1.0×106 D0¯¯¯D0 pairs from 281 pb−1 of e+e− collision data collected with the CLEO-c detector at Ecm=3.77 GeV. By combining CLEO-c measurements with branching fraction input and time-integrated measurements of RM≡(x2+y2)/2 and RWS≡Γ(D0→K+π−)/Γ(¯¯¯D0→K+π−) from other experiments, we find cosδ=1.03+0.31−0.17±0.06, where the uncertainties are statistical and systematic, respectively. In addition, by further including external measurements of charm mixing parameters, we obtain an alternate measurement of cosδ=1.10±0.35±0.07, as well as xsinδ=(4.4+2.7−1.8±2.9)×10−3 and δ=(22+11+9−12−11)°.1 MoreReceived 18 February 2008DOI:https://doi.org/10.1103/PhysRevD.78.012001©2008 American Physical Society

We present measurements of D--> KS0 pi and D--> KL0 pi branching fractions using 281 pb(-1) of psi(3770) data at the CLEO-c experiment. We find that B(D0--> KS0 pi 0) is larger than B(D0--> KL0 pi 0), with an asymmetry of R(D0)=0.108+/-0.025+/-0.024. For B(D+--> KS0 pi+) and B(D+--> KL0 pi+), we observe no measurable difference; the asymmetry is R(D+)=0.022+/-0.016+/-0.018. The D0 asymmetry is consistent with the value based on the U-spin prediction A(D0--> K0 pi 0)/A(D0--> K0 pi 0)=-tan2 theta C, where theta C is the Cabibbo angle.

Using $\ensuremath{\psi}(3770)\ensuremath{\rightarrow}D\overline{D}$ events collected with the CLEO-c detector at the Cornell ${e}^{+}{e}^{\ensuremath{-}}$ storage ring, tagged by fully reconstructing one $D$ meson in a hadronic decay mode, we measure absolute branching fractions and differential decay rates for ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$, ${D}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{e}^{+}{\ensuremath{\nu}}_{e}$, ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e}$, and ${D}^{+}\ensuremath{\rightarrow}{\overline{K}}^{0}{e}^{+}{\ensuremath{\nu}}_{e}$. The measured decay rates are used to study semileptonic form factors governing these transitions and to test unquenched Lattice QCD (LQCD) calculations. We average our results with previously published CLEO-c measurements of the same quantities using a neutrino reconstruction technique. Combining LQCD calculations of form factor absolute normalizations ${f}_{+}(0)$ and measurements of ${f}_{+}^{\ensuremath{\pi}}(0)|{V}_{cd}|$ and ${f}_{+}^{K}(0)|{V}_{cs}|$, we find $|{V}_{cd}|=0.222(8)(3)(23)$ and $|{V}_{cs}|=1.018(10)(8)(106)$, where the uncertainties are statistical, experimental systematic, and from LQCD, respectively.

Using CLEO data, we study the production of the antideuteron, ¯d, in Υ(nS) resonance decays and the nearby continuum. The branching ratios obtained are Bdir(Υ(1S)→¯dX)=(3.36±0.23±0.25)×10−5, B(Υ(1S)→¯dX)=(2.86±0.19±0.21)×10−5, and B(Υ(2S)→¯dX)=(3.37±0.50±0.25)×10−5, where the "dir" superscript indicates that decays produced via reannihilation of the b¯b pair to a γ∗ are removed from both the signal and the normalizing number of Υ(1S) decays in order to isolate direct decays of the Υ(1S) to ggg, ggγ. Upper limits at 90% C.L. are given for B(Υ(4S)→¯dX)<1.3×10−5, and continuum production σ(e+e−→¯dX)<0.031 pb. The Υ(2S) data is also used to extract a limit on χbJ→¯dX. The results indicate enhanced deuteron production in ggg, ggγ hadronization compared to γ∗→q¯q. Baryon number compensation is also investigated with the large Υ(1S)→¯dX sample.Received 10 December 2006DOI:https://doi.org/10.1103/PhysRevD.75.012009©2007 American Physical Society

The first measurements of the coherence factors (R_Kpipi0 and R_K3pi) and the average strong-phase differences (delta_D^Kpipi0 and delta_D^K3pi) for D0->K-pi+pi0 and D0->K-pi+pi+pi- are presented. These parameters can be used to improve the determination of the unitarity triangle angle gamma in B^- -> DK^- decays, where D is a D^0 or Dbar^0 meson decaying to the same final state. The measurements are made using quantum-correlated, fully-reconstructed D^0Dbar^0 pairs produced in e+e- collisions at the psi(3770) resonance. The measured values are: R_Kpipi0=0.84+/-0.07, delta_D^Kpipi0=(227+14-17) deg, $R_K3pi=0.33+0.20-0.23, and delta_D^K3pi=(114+26-23) deg. These results indicate significant coherence in the decay D0->K-pi+pi0, whereas lower coherence is observed in the decay D0->K-pi+pi+pi-. The analysis also results in a small improvement in the knowledge of other D-meson parameters, in particular the strong-phase difference for D0->K-pi+, delta_D^Kpi, and the mixing parameter, y.

Using ψ(2S)→π+π−J/ψ, J/ψ→γη′ events acquired with the CLEO-c detector at the CESR e+e− collider, we make the first observations of the decays η′→π+π−π0 and η′→π+π−e+e−, measuring absolute branching fractions (37+11−9±4)×10−4 and (25+12−9±5)×10−4, respectively. For η′→π+π−π0, this result probes the mechanism of isospin violation and the roles of π0/η/η′-mixing and final state rescattering in strong decays. We also set upper limits on branching fractions for η′ decays to π+π−μ+μ−, 2(π+π−), π+π−2π0, 2(π+π−)π0, 3(π+π−), and invisible final states.Received 15 September 2008DOI:https://doi.org/10.1103/PhysRevLett.102.061801©2009 American Physical Society

We analyze a sample of 3 million quantum-correlated D0 D0bar pairs from 818 pb^-1 of e+e- collision data collected with the CLEO-c detector at E_cm = 3.77 GeV, to give an updated measurement of \cos\delta and a first determination of \sin\delta, where \delta is the relative strong phase between doubly Cabibbo-suppressed D0 --> K+pi- and Cabibbo-favored D0bar --> K+pi- decay amplitudes. With no inputs from other experiments, we find \cos\delta = 0.81 +0.22+0.07 -0.18-0.05, \sin\delta = -0.01 +- 0.41 +- 0.04, and |\delta| = 10 +28+13 -53-0 degrees. By including external measurements of mixing parameters, we find alternative values of \cos\delta = 1.15 +0.19+0.00 -0.17-0.08, \sin\delta = 0.56 +0.32+0.21 -0.31-0.20, and \delta = (18 +11-17) degrees. Our results can be used to improve the world average uncertainty on the mixing parameter y by approximately 10%.

As part of the Snowmass process, the Cosmic Frontier WIMP Direct Detection subgroup (CF1) has drawn on input from the Cosmic Frontier and the broader Particle Physics community to produce this document. The charge to CF1 was (a) to summarize the current status and projected sensitivity of WIMP direct detection experiments worldwide, (b) motivate WIMP dark matter searches over a broad parameter space by examining a spectrum of WIMP models, (c) establish a community consensus on the type of experimental program required to explore that parameter space, and (d) identify the common infrastructure required to practically meet those goals.

A measurement of absolute integrated luminosity is presented using the CLEO II detector operating at the CESR e+e− storage ring. Independent analyses of three different final states (e+e−, γγ, and μ+μ−) at √s ⋍ 10 GeV normalize to the expected theoretical cross sections and correct for detection efficiencies. The resulting luminosities are measured with systematic errors of ±1.8%, ±1.6%, and ±2.2%, respectively, and are consistent with one another. The combined luminosity has a systematic error of ±1.0%.

Using CLEO data collected from CESR e+e− collisions at the ψ(2S) resonance and nearby continuum at √s=3.67 GeV, we report the first significantly nonzero measurements of light vector-pseudoscalar hadron pair production (including ρπ, ωπ, ρη, and K*0¯¯¯¯¯K0) and the π+π−π0 final state, both from ψ(2S) decays and direct e+e− annihilation.Received 14 July 2004DOI:https://doi.org/10.1103/PhysRevLett.94.012005©2005 American Physical Society

From e+e− collision data acquired with the CLEO detector at the Cornell Electron Storage Ring, we observe the non-D¯¯¯D decay ψ(3770)→γχc1 with a statistical significance of 6.6 standard deviations, using the two-photon cascades to J/ψ and J/ψ→ℓ+ℓ−. We determine σ(e+e−→ψ(3770))×B(ψ(3770)→γχc1)=(18.0±3.3±2.5) pb and branching fraction B(ψ(3770)→γχc1)=(2.8±0.5±0.4)×10−3. We set 90% C.L. upper limits for the transition to χc2 (χc0): σ×B<5.7 pb (<282 pb) and B<0.9×10−3 (<44×10−3). We also determine Γ(ψ(3770)→γχc1)/Γ(ψ(3770)→π+π−J/ψ)=1.5±0.3±0.3 (>1.0 at 90% C.L.), which bears upon the interpretation of X(3872).Received 21 September 2005DOI:https://doi.org/10.1103/PhysRevLett.96.182002©2006 American Physical Society

We describe new measurements of the inclusive and exclusive branching fractions for ψ(2S) transitions to J/ψ using e+e− collision data collected with the CLEO detector operating at CESR. All branching fractions and ratios of branching fractions reported here represent either the most precise measurements to date or the first direct measurements. Indirectly and in combination with other CLEO measurements, we determine B(χcJ→γJ/ψ) and B[ψ(2S)→light hadrons].Received 16 March 2005DOI:https://doi.org/10.1103/PhysRevLett.94.232002©2005 American Physical Society

The decay psi(2S) --> eta J/psi is used to measure, for the first time, all prominent eta-meson branching fractions with the same experiment in the same dataset, thereby providing a consistent treatment of systematics across branching fractions. We present results for eta decays to gamma gamma, pi+pi-pi0, 3 pi0, pi+ pi- gamma, and e+ e- gamma, accounting for 99.9% of all eta decays. The precisions for several of the branching fractions and their ratios are improved. Two channels, pi+ pi- gamma and e+ e- gamma, show results that differ at the level of three standard deviations from those previously determined.

We present measurements of decay matrix elements for hadronic transitions of the form Υ(nS)→Υ(mS)ππ, where (n,m)=(3,1),(2,1),(3,2). We reconstruct charged and neutral pion modes with the final state Upsilon decaying to either μ+μ− or e+e−. Dalitz plot distributions for the 12 decay modes are fit individually as well as jointly assuming isospin symmetry, thereby measuring the matrix elements of the decay amplitude. We observe and account for the anomaly previously noted in the dipion invariant mass distribution for the Υ(3S)→Υ(1S)ππ transition and obtain good descriptions of the dynamics of the decay using the most general decay amplitude allowed by partial conservation of the axial-vector current considerations. The fits further indicate that the Υ(2S)→Υ(1S)ππ and Υ(3S)→Υ(2S)ππ transitions also show the presence of terms in the decay amplitude that were previously ignored, although at a relatively suppressed level.5 MoreReceived 15 June 2007DOI:https://doi.org/10.1103/PhysRevD.76.072001©2007 American Physical Society

Using $281\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of data recorded by the CLEO-c detector in ${e}^{+}{e}^{\ensuremath{-}}$ collisions at the $\ensuremath{\psi}(3770)$, corresponding to $0.78\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${D}^{+}{D}^{\ensuremath{-}}$ pairs, we investigate the substructure of the decay ${D}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ using the Dalitz plot technique. We find that our data are consistent with the following intermediate states: $\ensuremath{\rho}(770){\ensuremath{\pi}}^{+}$, ${f}_{2}(1270){\ensuremath{\pi}}^{+}$, ${f}_{0}(1370){\ensuremath{\pi}}^{+}$, ${f}_{0}(1500){\ensuremath{\pi}}^{+}$, ${f}_{0}(980){\ensuremath{\pi}}^{+}$, and $\ensuremath{\sigma}{\ensuremath{\pi}}^{+}$. We confirm large $S$ wave contributions at low $\ensuremath{\pi}\ensuremath{\pi}$ mass. We set upper limits on contributions of other possible intermediate states. We consider three models of the $\ensuremath{\pi}\ensuremath{\pi}$ $S$ wave and find that all of them adequately describe our data.

Using a sample of tagged D+s decays collected near the D*±sD∓s peak production energy in e+e− collisions with the CLEO-c detector, we study the leptonic decay D+s→τ+ντ via the decay channel τ+→e+νe¯ντ. We measure B(D+s→τ+ντ)=(6.17±0.71±0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of D+s→μ+νμ and D+s→τ+ντ (via τ+→π+¯ντ), we determine fDs=(274±10±5) MeV.Received 7 December 2007DOI:https://doi.org/10.1103/PhysRevLett.100.161801©2008 American Physical Society

We measure the absolute branching fractions of Ds semileptonic decays where the hadron in the final state is one of ϕ, η, η′, K0S, K⋆0, and f0, using 2.8×105 e+e−→DsD⋆s decays collected in the CLEO-c detector at a center-of-mass energy close to 4170 MeV. We obtain B(D+s→ϕe+νe)=(2.29±0.37±0.11)%, B(D+s→ηe+νe)=(2.48±0.29±0.13)%, B(D+s→η′e+νe)=(0.91±0.33±0.05)%, where the first uncertainties are statistical and the second are systematic. We also obtain B(D+s→K0e+νe)=(0.37±0.10±0.02)%, and B(D+s→K⋆0e+νe)=(0.18±0.07±0.01)%, which are the first measurements of Cabibbo suppressed exclusive Ds semileptonic decays, and, B(D+s→f0e+νe)×B(f0→π+π−)=(0.13±0.04±0.01)%. This is the first absolute product branching fraction determination for a semileptonic decay including a scalar meson in the final state.Received 3 March 2009DOI:https://doi.org/10.1103/PhysRevD.80.052007©2009 American Physical Society

Using a data sample of $24.5\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\psi}(2S)$ the reactions $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{cJ}$, ${\ensuremath{\chi}}_{cJ}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$ have been studied for the first time to determine the two-photon widths of the ${\ensuremath{\chi}}_{cJ}$ states of charmonium in their decay into two photons. The measured quantities are $\mathcal{B}(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c0})\ifmmode\times\else\texttimes\fi{}\mathcal{B}({\ensuremath{\chi}}_{c0}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})=(2.17\ifmmode\pm\else\textpm\fi{}0.32\ifmmode\pm\else\textpm\fi{}0.10)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ and $\mathcal{B}(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c2})\ifmmode\times\else\texttimes\fi{}\mathcal{B}({\ensuremath{\chi}}_{c2}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})=(2.68\ifmmode\pm\else\textpm\fi{}0.28\ifmmode\pm\else\textpm\fi{}0.15)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. Using values for $\mathcal{B}(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c0,c2})$ and $\ensuremath{\Gamma}({\ensuremath{\chi}}_{c0,c2})$ from the literature the two-photon widths are derived to be ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c0})=(2.36\ifmmode\pm\else\textpm\fi{}0.35\ifmmode\pm\else\textpm\fi{}0.22)\text{ }\text{ }\mathrm{keV}$, ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c2})=(0.66\ifmmode\pm\else\textpm\fi{}0.07\ifmmode\pm\else\textpm\fi{}0.06)\text{ }\text{ }\mathrm{keV}$, and $\mathcal{R}\ensuremath{\equiv}{\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c2})/{\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c0})=0.278\ifmmode\pm\else\textpm\fi{}0.050\ifmmode\pm\else\textpm\fi{}0.036$. The importance of the measurement of $\mathcal{R}$ is emphasized. For the forbidden transition, ${\ensuremath{\chi}}_{c1}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$, an upper limit of ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c1})&lt;0.03\text{ }\text{ }\mathrm{keV}$ is established.

Using a data sample of 2.59 x 10^7 psi(2S) decays obtained with the CLEO-c detector, we perform amplitude analyses of the complementary decay chains chi_c1 -> eta pi+ pi- and chi_c1 -> eta' pi+ pi-. We find evidence for a P-wave eta' pi scattering amplitude, which, if interpreted as a resonance, would have exotic J^PC = 1^-+ and parameters consistent with the pi_1(1600) state reported in other production mechanisms. We also make the first observation of the decay a_0(980) -> eta' pi and measure the ratio of branching fractions B(a_0(980) -> eta' pi)/B(a_0(980) -> eta pi) = 0.064 +- 0.014 +- 0.014. The pi pi spectrum produced with a recoiling eta is compared to that with eta' recoil.

We report the first observation of the decay D + → η e + ν e in two analyses, which combined provide a branching fraction of B(D + → η e + ν e ) = (2.16 ± 0.53 ± 0.07) × 10 -4 .We also provide an improved measurement of B(D + → ηe + ν e ) = (11.4± 0.9 ± 0.4) × 10 -4 , provide the first form factor measurement, and set the improved upper limit B(D + → φ e + ν e ) < 0.9 × 10 -4 (90% C.L.).

The beauty to up quark coupling constant |V(ub)| can be extracted from B → ρ e+ ν(e) combined with the form factors for D → K* e+ ν(e) and B → V ℓ+ ℓ- and D → ρ e+ ν(e). Using the entire CLEO-c ψ(3770) → DD event sample, corresponding to an integrated luminosity of 818 pb(-1) and approximately 5.4×10(6) DD events, we measure the form factors for the decays D0 → ρ- e+ ν(e) and D+ → ρ0 e+ ν(e) for the first time and the branching fractions with improved precision. A four-dimensional unbinned maximum likelihood fit determines the form factor ratios to be V(0)/A1(0)=1.48±0.15±0.05 and A2(0)/A1(0)=0.83±0.11±0.04. Assuming Cabibbo-Kobayashi-Maskawa unitarity, the known D meson lifetimes, and our measured branching fractions we obtain the form factor normalizations A1(0), A2(0), and V(0). We also present a measurement of the branching fraction for D+ → ω e+ ν(e) with improved precision.

We have searched for the effective FCNC decays b->s l+l- using an inclusive method. We set upper limits on the branching ratios B(b->s e+e-) < 5.7 10^{-5}, B(b->s mu+mu-) < 5.8 10^{-5}, and B(b->s e+-mu-+) < 2.2 10^{-5} (at 90 %\ C.L.). Combining the di-electron and di-muon decay modes we find: B(b->s l+l-) < 4.2 10^{-5} (at 90 % C.L.).

We present a new determination of ${f}_{{D}_{s}}$ using 5 million ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}c\overline{c}$ events obtained with the CLEO II detector. Our value is derived from our new measured ratio $\ensuremath{\Gamma}{(D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}\ensuremath{\nu})/\ensuremath{\Gamma}{(D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+})=0.173\ifmmode\pm\else\textpm\fi{}0.023\ifmmode\pm\else\textpm\fi{}0.035$. Using $\mathcal{B}{(D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+})=(3.6\ifmmode\pm\else\textpm\fi{}0.9)$%, we extract ${f}_{{D}_{s}}=(280\ifmmode\pm\else\textpm\fi{}19\ifmmode\pm\else\textpm\fi{}28\ifmmode\pm\else\textpm\fi{}34) \mathrm{MeV}$. We compare this result with various model calculations.

Using the CLEO II detector at the Cornell Electron Storage Ring, we have searched for flavor changing neutral currents and lepton family number violations in ${D}^{0}$ meson decays. The upper limits on the branching fractions for ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ and ${D}^{0}\ensuremath{\rightarrow}{X}^{0}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ are in the range ${10}^{\ensuremath{-}5}$ to ${10}^{\ensuremath{-}4}$, where ${X}^{0}$ can be a ${\ensuremath{\pi}}^{0}$, ${K}_{s}^{0}$, $\ensuremath{\eta}$, ${\ensuremath{\rho}}^{0}$, $\ensuremath{\omega}$, ${\overline{K}}^{*0}$, or $\ensuremath{\varphi}$ meson, and the ${\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ pair can be ${e}^{+}{e}^{\ensuremath{-}}$, ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, or ${e}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\mu}}^{\ensuremath{\mp}}$. Although these limits are above the theoretical predictions, most are new or an order of magnitude lower than previous limits.

In 60 pb−1 of data taken on the ψ(3770) resonance with the CLEO-c detector, we find eight D+→μ+ν decay candidates that are mostly signal, containing only one estimated background. Using this statistically compelling sample, we measure a value of B(D+→μ+ν)=(3.5±1.4±0.6)×10−4, and determine fD+=(202±41±17) MeV.4 MoreReceived 11 November 2004DOI:https://doi.org/10.1103/PhysRevD.70.112004©2004 American Physical Society

With the first data sample collected by the CLEO-c detector at the ψ(3770) resonance we have studied four exclusive semileptonic decays of the D0 meson. Our results include the first observation and absolute branching fraction measurement for D0→ρ−e+νe and improved measurements of the absolute branching fractions for D0 decays to K−e+νe, π−e+νe, and K*−e+νe.Received 22 June 2005DOI:https://doi.org/10.1103/PhysRevLett.95.181802©2005 American Physical Society

Using 1.79 ${\mathrm{fb}}^{\mathrm{\ensuremath{-}}1}$ of data recorded by the CLEO II detector we have measured the absolute branching fraction for ${\mathit{D}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{\mathrm{\ensuremath{-}}}$${\mathrm{\ensuremath{\pi}}}^{+}$. The angular correlation between the ${\mathrm{\ensuremath{\pi}}}^{+}$ emitted in the decay ${\mathit{D}}^{\mathrm{*}+}$\ensuremath{\rightarrow}${\mathit{D}}^{0}$${\mathrm{\ensuremath{\pi}}}^{+}$, and the jet direction in ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}cc\ifmmode\bar\else\textasciimacron\fi{} events, is used to determine the total number of inclusive ${\mathit{D}}^{0}$ mesons produced from this source. The subsequent reconstruction of the decay chain ${\mathit{D}}^{\mathrm{*}+}$\ensuremath{\rightarrow}${\mathit{D}}^{0}$${\mathrm{\ensuremath{\pi}}}^{+}$,${\mathit{D}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{\mathrm{\ensuremath{-}}}$${\mathrm{\ensuremath{\pi}}}^{+}$ allows a measurement of the absolute ${\mathit{D}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{\mathrm{\ensuremath{-}}}$${\mathrm{\ensuremath{\pi}}}^{+}$ branching fraction. Correcting for decay radiation in the final state, we find scrB(${\mathit{D}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{\mathrm{\ensuremath{-}}}$${\mathrm{\ensuremath{\pi}}}^{+}$)=[3.95\ifmmode\pm\else\textpm\fi{}0.08(stat)\ifmmode\pm\else\textpm\fi{}0.17(syst)]%.

Using data collected at the psi(3770) resonance with the CLEO-c detector at the Cornell e+e- storage ring, we present improved measurements of the absolute branching fractions of D+ decays to K0B e+ nu_e, pi0 e+ nu_e, K0B* e+ nu_e, and rho0 e+ nu_e, and the first observation and absolute branching fraction measurement of D+ --> omega e+ nu_e. We also report the most precise tests to date of isospin invariance in semileptonic D0 and D+ decays.

We present measurements of the inclusive branching fractions for the decays ${D}^{+}\ensuremath{\rightarrow}X{e}^{+}{\ensuremath{\nu}}_{e}$ and ${D}^{0}\ensuremath{\rightarrow}X{e}^{+}{\ensuremath{\nu}}_{e}$, using $281\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of data collected on the $\ensuremath{\psi}(3770)$ resonance with the CLEO-c detector. We find $\mathcal{B}({D}^{0}\ensuremath{\rightarrow}X{e}^{+}{\ensuremath{\nu}}_{e})=(6.46\ifmmode\pm\else\textpm\fi{}0.17\ifmmode\pm\else\textpm\fi{}0.13)%$ and $\mathcal{B}({D}^{+}\ensuremath{\rightarrow}X{e}^{+}{\ensuremath{\nu}}_{e})=(16.13\ifmmode\pm\else\textpm\fi{}0.20\ifmmode\pm\else\textpm\fi{}0.33)%$. Using the known $D$ meson lifetimes, we obtain the ratio ${\ensuremath{\Gamma}}_{{D}^{+}}^{\mathrm{sl}}/{\ensuremath{\Gamma}}_{{D}^{0}}^{\mathrm{sl}}=0.985\ifmmode\pm\else\textpm\fi{}0.028\ifmmode\pm\else\textpm\fi{}0.015$, confirming isospin invariance at the level of 3%. The positron momentum spectra from ${D}^{+}$ and ${D}^{0}$ have consistent shapes.

Using data accumulated with the CLEO detector corresponding to an integrated luminosity of L=5.63 pb−1 on the peak of the ψ(2S) [3.08×106 ψ(2S) decays] and 20.70 pb−1 at √s=3.67 GeV, we report first measurements of the branching fractions for the following 13 decay modes of the ψ(2S): η3π, η′3π, ρK+K−, K+K−π+π−π0, 2(K+K−), 2(K+K−)π0, ρp¯p, p¯pπ+π−π0, ηp¯p, p¯pK+K−, Λ¯¯¯Λπ+π−, Λ¯pK+, and Λ¯pK+π+π−, and more precise measurements of 8 previously measured modes: 2(π+π−), ρπ+π−, 2(π+π−)π0, ωπ+π−, K+K−π+π−, ωK+K−, ϕK+K−, and p¯pπ+π−. We also report new branching fraction measurements of ϕπ+π− and ωp¯p and upper limits for ηπ+π−, ηK+K−, and ϕp¯p. Results are compared, where possible, with the corresponding J/ψ branching ratios to provide new tests of the 12% rule.Received 31 May 2005DOI:https://doi.org/10.1103/PhysRevLett.95.062001©2005 American Physical Society

We report on a search for CP asymmetry in the singly Cabibbo-suppressed decay D+→K+K−π+ using a data sample of 818 pb−1 accumulated with the CLEO-c detector on the ψ(3770) resonance. A Dalitz-plot analysis is used to determine the amplitudes of the intermediate states. We find no evidence for CP violation either in specific two-body amplitudes or integrated over the entire phase space. The CP asymmetry in the latter case is measured to be (−0.03±0.84±0.29)%.Received 28 July 2008DOI:https://doi.org/10.1103/PhysRevD.78.072003©2008 American Physical Society

We exploit the quantum coherence between pair-produced D0 and D0bar in psi(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase \delta between D0 -> K+pi- and D0bar -> K+pi-. Using 281 pb^-1 of e^+e^- collision data collected with the CLEO-c detector at E_cm = 3.77 GeV, as well as branching fraction input and time-integrated measurements of R_M = (x^2+y^2)/2 and R_{WS} = Gamma(D0 -> K+pi-)/Gamma(D0bar -> K+pi-) from other experiments, we find \cos\delta = 1.03 +0.31-0.17 +- 0.06, where the uncertainties are statistical and systematic, respectively. By further including other mixing parameter measurements, we obtain an alternate measurement of \cos\delta = 1.10 +- 0.35 +- 0.07, as well as x\sin\delta = (4.4 +2.7-1.8 +- 2.9) x 10^-3 and \delta = 22 +11-12 +9-11 degrees.

Using a sample of 1.8 million DD¯ mesons collected at the ψ(3770) with the CLEO-c detector, we study the semileptonic decays D0→π−e+νe, D+→π0e+νe, D0→K−e+νe, and D+→K¯0e+νe. For the total branching fractions we find B(D0→π−e+νe)=0.299(11)(9)%, B(D+→π0e+νe)=0.373(22)(13)%, B(D0→K−e+νe)=3.56(3)(9)%, and B(D+→K¯0e+νe)=8.53(13)(23)%, where the first error is statistical and the second systematic. In addition, form factors are studied through fits to the partial branching fractions obtained in five q2 ranges. By combining our results with recent unquenched lattice calculations, we obtain |Vcd|=0.217(9)(4)(23) and |Vcs|=1.015(10)(11)(106), where the final error is theoretical.Received 5 December 2007DOI:https://doi.org/10.1103/PhysRevD.77.112005©2008 American Physical Society

In this Letter we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays of Upsilon(nS)(n=1,2, and 3) into muon and tau using the data collected with the CLEO III detector. We identify the tau lepton using its leptonic decay into electron and utilize multidimensional likelihood fitting with PDF shapes measured from independent data samples. We report our estimates of 95% CL upper limits on LFV branching fractions of Upsilon mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.

Using $24\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${\ensuremath{\psi}}^{\ensuremath{'}}\ensuremath{\equiv}\ensuremath{\psi}(2S)$ decays in CLEO-c, we have searched for higher multipole admixtures in electric-dipole-dominated radiative transitions in charmonia. We find good agreement between our data and theoretical predictions for magnetic quadrupole ($M2$) amplitudes in the transitions ${\ensuremath{\psi}}^{\ensuremath{'}}\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c1,c2}$ and ${\ensuremath{\chi}}_{c1,c2}\ensuremath{\rightarrow}\ensuremath{\gamma}J/\ensuremath{\psi}$, in striking contrast to some previous measurements. Let ${b}_{2}^{J}$ and ${a}_{2}^{J}$ denote the normalized $M2$ amplitudes in the respective aforementioned decays, where the superscript $J$ refers to the angular momentum of the ${\ensuremath{\chi}}_{cJ}$. By performing unbinned maximum likelihood fits to full five-parameter angular distributions, we found the following values of $M2$ admixtures for ${J}_{\ensuremath{\chi}}=1$: ${a}_{2}^{J=1}=(\ensuremath{-}6.26\ifmmode\pm\else\textpm\fi{}0.63\ifmmode\pm\else\textpm\fi{}0.24)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$ and ${b}_{2}^{J=1}=(2.76\ifmmode\pm\else\textpm\fi{}0.73\ifmmode\pm\else\textpm\fi{}0.23)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, which agree well with theoretical expectations for a vanishing anomalous magnetic moment of the charm quark. For ${J}_{\ensuremath{\chi}}=2$, if we fix the electric octupole ($E3$) amplitudes to zero as theory predicts for transitions between charmonium $S$ states and $P$ states, we find ${a}_{2}^{J=2}=(\ensuremath{-}9.3\ifmmode\pm\else\textpm\fi{}1.6\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$ and ${b}_{2}^{J=2}=(1.0\ifmmode\pm\else\textpm\fi{}1.3\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$. If we allow for $E3$ amplitudes we find, with a four-parameter fit, ${a}_{2}^{J=2}=(\ensuremath{-}7.9\ifmmode\pm\else\textpm\fi{}1.9\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, ${b}_{2}^{J=2}=(0.2\ifmmode\pm\else\textpm\fi{}1.4\ifmmode\pm\else\textpm\fi{}0.4)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, ${a}_{3}^{J=2}=(1.7\ifmmode\pm\else\textpm\fi{}1.4\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, and ${b}_{3}^{J=2}=(\ensuremath{-}0.8\ifmmode\pm\else\textpm\fi{}1.2\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$. We determine the ratios ${a}_{2}^{J=1}/{a}_{2}^{J=2}={0.67}_{\ensuremath{-}0.13}^{+0.19}$ and ${a}_{2}^{J=1}/{b}_{2}^{J=1}=\ensuremath{-}{2.27}_{\ensuremath{-}0.99}^{+0.57}$, where the theoretical predictions are independent of the charmed quark magnetic moment and are ${a}_{2}^{J=1}/{a}_{2}^{J=2}=0.676\ifmmode\pm\else\textpm\fi{}0.071$ and ${a}_{2}^{J=1}/{b}_{2}^{J=1}=\ensuremath{-}2.27\ifmmode\pm\else\textpm\fi{}0.16$.

We perform a Dalitz plot analysis of the decay ${D}_{s}^{+}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ with the CLEO-c data set of $586\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collisions accumulated at $\sqrt{s}=4.17\text{ }\text{ }\mathrm{GeV}$. This corresponds to about $0.57\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${D}_{s}^{\ifmmode\pm\else\textpm\fi{}}{D}_{s}^{*\ensuremath{\mp}}$ pairs from which we select 14 400 candidates with a background of roughly 15%. In contrast to previous measurements we find good agreement with our data only by including an additional ${f}_{0}(1370){\ensuremath{\pi}}^{+}$ contribution. We measure the magnitude, phase, and fit fraction of ${K}^{*}(892{)}^{0}{K}^{+}$, $\ensuremath{\phi}(1020){\ensuremath{\pi}}^{+}$, ${K}_{0}^{*}(1430){K}^{+}$, ${f}_{0}(980){\ensuremath{\pi}}^{+}$, ${f}_{0}(1710){\ensuremath{\pi}}^{+}$, and ${f}_{0}(1370){\ensuremath{\pi}}^{+}$ contributions and limit the possible contributions of other $KK$ and $K\ensuremath{\pi}$ resonances that could appear in this decay.

The first flavor-tagged amplitude analysis of the decay ${D}^{0}$ to the self-conjugate final state ${K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ is presented. Approximately 3000 signal decays are selected from data acquired by the CLEO II.V, CLEO III, and CLEO-c detectors. The three most significant amplitudes, which contribute to the model that best fits the data, are $\ensuremath{\phi}{\ensuremath{\rho}}^{0}$, ${K}_{1}(1270{)}^{\ifmmode\pm\else\textpm\fi{}}{K}^{\ensuremath{\mp}}$, and nonresonant ${K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$. Separate amplitude analyses of ${D}^{0}$ and ${\overline{D}}^{0}$ candidates indicate no $CP$ violation among the amplitudes at the level of 5% to 30% depending on the mode. In addition, the sensitivity to the $CP$-violating parameter $\ensuremath{\gamma}/{\ensuremath{\phi}}_{3}$ from a sample of 2000 ${B}^{+}\ensuremath{\rightarrow}{\stackrel{\texttildelow{}}{D}}^{0}({K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}){K}^{+}$ decays, where $\stackrel{\texttildelow{}}{D}$ is a ${D}^{0}$ or ${\overline{D}}^{0}$, collected at LHCb or a future flavor facility, is estimated to be $(11.3\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode^\circ\else\textdegree\fi{}$ using the favored model.

The first measurements of the coherence factor R_{K_S^0Kπ} and the average strong--phase difference δ^{K_S^0Kπ} in D^0 \to K_S^0 K^\mpπ^\pm decays are reported. These parameters can be used to improve the determination of the unitary triangle angle γ in B^- \rightarrow $\widetilde{D}K^-$ decays, where $\widetilde{D}$ is either a D^0 or a D^0-bar meson decaying to the same final state, and also in studies of charm mixing. The measurements of the coherence factor and strong-phase difference are made using quantum-correlated, fully-reconstructed D^0D^0-bar pairs produced in e^+e^- collisions at the ψ(3770) resonance. The measured values are R_{K_S^0Kπ} = 0.70 \pm 0.08 and δ^{K_S^0Kπ} = (0.1 \pm 15.7)$^\circ$ for an unrestricted kinematic region and R_{K*K} = 0.94 \pm 0.12 and δ^{K*K} = (-16.6 \pm 18.4)$^\circ$ for a region where the combined K_S^0 π^\pm invariant mass is within 100 MeV/c^2 of the K^{*}(892)^\pm mass. These results indicate a significant level of coherence in the decay. In addition, isobar models are presented for the two decays, which show the dominance of the K^*(892)^\pm resonance. The branching ratio {B}(D^0 \rightarrow K_S^0K^+π^-)/{B}(D^0 \rightarrow K_S^0K^-π^+) is determined to be 0.592 \pm 0.044 (stat.) \pm 0.018 (syst.), which is more precise than previous measurements.

We search for the decays ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ in a sample of $2.2\ifmmode\times\else\texttimes\fi{}{10}^{6}$ charged $B$ decays using the CLEO detector. We see no evidence for a signal in any channel and set upper limits on the branching fractions of $B({B}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}})&lt;2.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, $B({B}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}})&lt;2.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$, and $B({B}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{e})&lt;1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ at the 90% confidence level.

Using data collected with the CLEO II detector at the Cornell Electron Storage Ring, we have studied the decays of leptons produced through e ϩ e Ϫ annihilation into final states containing K S 0 mesons, observed through their decays to ϩ Ϫ .We present branching fractions for decays to five final states: Ϫ →K 0 h Ϫ , Ϫ →K 0 h Ϫ 0 , Ϫ →K 0 K Ϫ , Ϫ →K 0 K Ϫ 0 , and Ϫ →K S 0 K S 0 h Ϫ , where K 0 h Ϫ denotes the sum of the processes involving K ¯0 Ϫ and K 0 K Ϫ particle combinations.Substructure and mass spectra in these final states are also addressed.

The angular distributions of the decay Λ+c→Λe+νe have been studied using the CLEO II detector. By performing a three-dimensional maximum likelihood fit, the form factor ratio R=f2/f1 is determined to be −0.25±0.14±0.08. The decay asymmetry parameter of the Λc averaged over q2 is calculated to be αΛc=−0.82+0.09+0.06−0.06−0.03.Received 13 January 1995DOI:https://doi.org/10.1103/PhysRevLett.75.624©1995 American Physical Society

Using data from the CLEO II detector at CESR, we measure ${\cal B}(\tau^\pm\rightarrow h^\pm\pi^0\nu_\tau)$ where $h^\pm$ refers to either $\pi^\pm$ or $K^\pm$. We use three different methods to measure this branching fraction. The combined result is ${\cal B}(\tau^\pm\rightarrow h^\pm\pi^0\nu_\tau) = 0.2587 \pm 0.0012 \pm 0.0042$, in good agreement with Standard Model predictions. This result, in combination with other precision measurements, reduces the significance of the one-prong problem in tau decays. A postscript version is available through World-Wide-Web in http://w4.lns.cornell.edu/public/CLNS/1994/

We use data collected by the CLEO III detector at CESR on the Upsilon(5S) resonance to measure the inclusive yield of Ds mesons. Comparing with data taken on the Upsilon(4S), which decays into lighter B mesons, we make a model dependent estimate of the ratio of Bs(*)anti-Bs(*) to the total b anti-b quark pair production at the Upsilon(5S) energy of (16.0+/-2.6+/-5.8)%.

We examine e+e- --> Ds- Ds*+ and Ds*- Ds+ interactions at 4170 MeV using the CLEO-c detector in order to measure the decay constant fDs+. We use the Ds+ --> l+ nu channel, where the l+ designates either a mu+ or a tau+, when the tau+ --> pi+ nu. Analyzing both modes independently, we determine B(Ds+ --> mu+ nu) = (0.594 +- 0.066 +- 0.031)%, and B(Ds+ --> tau+ nu) = (8.0 +- 1.3 +- 0.4)%. We also analyze them simultaneously to find an effective value of B{eff}(Ds+ --> mu+ nu) = (0.638 +- 0.059 +- 0.033)% and extract fDs = (274 +- 13 +- 7) MeV. Combining with our previous determination of B(D+ -> mu+ nu), we also find the ratio fDs/fD+ = 1.23 +- 0.11 +- 0.04. We compare to current theoretical estimates. Finally, we find B(Ds+ --> e+ nu) < 1.3 x10^{-4} at 90% confidence level.

Using the CLEO III detector, we measure absolute cross sections for e + e -→ hadrons at seven center-of-mass energies between 6.964 and 10.538 GeV.The values of R, the ratio of hadronic and muon pair production cross sections, are determined within 2% total r.m.s.uncertainty.

Using data collected at the ψ(3770) resonance with the CLEO-c detector at the Cornell e+e− storage ring, we present searches for 25 charmless decay modes of the ψ(3770), mostly multibody final states. No evidence for charmless decays is found.Received 29 September 2005DOI:https://doi.org/10.1103/PhysRevLett.96.032003©2006 American Physical Society

We report the first observation of the decay J/ψ→3γ. The signal has a statistical significance of 6σ and corresponds to a branching fraction of B(J/ψ→3γ)=(1.2±0.3±0.2)×10−5, in which the errors are statistical and systematic, respectively. The measurement uses ψ(2S)→π+π−J/ψ events acquired with the CLEO-c detector operating at the CESR e+e− collider.Received 3 June 2008DOI:https://doi.org/10.1103/PhysRevLett.101.101801©2008 American Physical Society