K. M. Ecklund

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 13.5 ${\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data collected with the CLEO II detector, we have observed a narrow resonance decaying to ${D}_{s}^{*+}{\ensuremath{\pi}}^{0}$ with a mass near $2.46\mathrm{GeV}{/c}^{2}.$ The search for such a state was motivated by the recent discovery by the BaBar Collaboration of a narrow state at $2.32\mathrm{GeV}{/c}^{2},$ the ${D}_{\mathrm{sJ}}^{*}{(2317)}^{+},$ that decays to ${D}_{s}^{+}{\ensuremath{\pi}}^{0}.$ Reconstructing the ${D}_{s}^{+}{\ensuremath{\pi}}^{0}$ and ${D}_{s}^{*+}{\ensuremath{\pi}}^{0}$ final states in CLEO data, we observe peaks in both of the corresponding reconstructed mass difference distributions, $\ensuremath{\Delta}{M(D}_{s}{\ensuremath{\pi}}^{0}{)=M(D}_{s}{\ensuremath{\pi}}^{0})\ensuremath{-}{M(D}_{s})$ and $\ensuremath{\Delta}{M(D}_{s}^{*}{\ensuremath{\pi}}^{0}{)=M(D}_{s}^{*}{\ensuremath{\pi}}^{0})\ensuremath{-}{M(D}_{s}^{*}),$ both of them at values near $350\mathrm{MeV}{/c}^{2}.$ We interpret these peaks as signatures of two distinct states, the ${D}_{\mathrm{sJ}}^{*}{(2317)}^{+}$ plus a new state, designated as the ${D}_{\mathrm{sJ}}{(2463)}^{+}.$ Because of the similar $\ensuremath{\Delta}M$ values, each of these states represents a source of background for the other if photons are lost, ignored or added. A quantitative accounting of these reflections confirms that both states exist. We have measured the mean mass differences $〈\ensuremath{\Delta}{M(D}_{s}{\ensuremath{\pi}}^{0})〉=350.0\ifmmode\pm\else\textpm\fi{}1.2(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.0(\mathrm{syst})\mathrm{MeV}{/c}^{2}$ for the ${D}_{\mathrm{sJ}}^{*}{(2317)}^{+}$ state, and $〈\ensuremath{\Delta}{M(D}_{s}^{*}{\ensuremath{\pi}}^{0})〉=351.2\ifmmode\pm\else\textpm\fi{}1.7(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.0(\mathrm{syst})\mathrm{MeV}{/c}^{2}$ for the new ${D}_{\mathrm{sJ}}{(2463)}^{+}$ state. We have also searched, but find no evidence, for decays of the two states via the channels ${D}_{s}^{*+}\ensuremath{\gamma},{D}_{s}^{+}\ensuremath{\gamma},$ and ${D}_{s}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}.$ The observations of the two states at 2.32 and $2.46\mathrm{GeV}{/c}^{2},$ in the ${D}_{s}^{+}{\ensuremath{\pi}}^{0}$ and ${D}_{s}^{*+}{\ensuremath{\pi}}^{0}$ decay channels, respectively, are consistent with their interpretations as $c\overline{s}$ mesons with an orbital angular momentum $L=1$ and spin and parity ${J}^{P}{=0}^{+}$ and ${1}^{+}.$

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.

The CLEO group at the Cornell Electron Storage Ring has constructed and commissioned a new central drift chamber. With 9796 cells arranged in 47 layers ranging in radius from 13.2 to 79cm, the new drift chamber has a smaller outer radius and fewer wires than the drift chamber it replaces, but allows the CLEO tracking system to have improved momentum resolution. Reduced scattering material in the chamber gas and in the inner skin separating the drift chamber from the silicon vertex detector provides a reduction of the multiple scattering component of the momentum resolution and an extension of the usable measurement length into the silicon. Momentum resolution is further improved through quality control in wire positioning and symmetry of the electric fields in the drift cells which have provided a reduction in the spatial resolution to 88μm (averaged over the full drift range).

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 ${\ensuremath{\Gamma}}_{ee}(Y(4260))\ifmmode\times\else\texttimes\fi{}\mathcal{B}(Y(4260)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi})=({8.9}_{\ensuremath{-}3.1}^{+3.9}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.8(\mathrm{syst}))\text{ }\text{ }\mathrm{eV}/{c}^{2}$.

We present the first measurement of the D*+ width using 9/fb of e+ e- data collected near the Upsilon(4S) resonance by the CLEO II.V detector. Our method uses advanced tracking techniques and a reconstruction method that takes advantage of the small vertical size of the CESR beam spot to measure the energy release distribution from the D*+ -> D0 pi+ decay. We find Gamma(D*+) = 96 +- 4 (Statistical) +- 22 (Systematic) keV. We also measure the energy release in the decay and compute Delta m = m(D*+) - m(D0) = 145.412 +- 0.002 (Statistical) +- 0.012 (Systematic) MeV/c^2

We have studied exclusive, radiative B meson decays to charmless mesons in 9.7x10(6) B&Bmacr; decays accumulated with the CLEO detector. We measure B(B0-->K(*0)(892)gamma) = (4.55(+0.72)(-0. 68)+/-0.34)x10(-5) and B(B+-->K(*+)(892)gamma) = (3.76(+0.89)(-0. 83)+/-0.28)x10(-5). We have searched for CP asymmetry in B-->K(*)(892)gamma decays and measure A(CP) = +0.08+/-0.13+/-0.03. We report the first observation of B-->K(*)(2)(1430)gamma decays with a branching fraction of (1.66(+0.59)(-0.53)+/-0.13)x10(-5). No evidence for the decays B-->rhogamma and B0-->omegagamma is found and we limit B(B-->(rho/omega)gamma)/B(B-->K(*)(892)gamma)<0.32 at 90% C.L.

We use data collected with the CLEO II detector to perform a high-statistics measurement of the resonant substructure in ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}$ decays. We find that the Dalitz plot is well represented by a combination of seven quasi-two-body decay channels $[{K}^{*0}{\ensuremath{\pi}}^{0},{K}^{\ensuremath{-}}\ensuremath{\rho},{K}^{*\ensuremath{-}}{\ensuremath{\pi}}^{+},{K}_{0}{(1430)}^{\ensuremath{-}}{\ensuremath{\pi}}^{+},{K}_{0}{(1430)}^{0}{\ensuremath{\pi}}^{0},{K}^{\ensuremath{-}}{\ensuremath{\rho}}^{+}(1700),$ and ${K}^{*}{(1680)}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}],$ plus a small non-resonant component. We see no evidence of a scalar $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\kappa}}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ resonance in the mass range recently reported by other groups. Using the amplitudes and phases from this analysis, we calculate an integrated $\mathrm{CP}$ asymmetry of $\ensuremath{-}0.031\ifmmode\pm\else\textpm\fi{}0.086.$

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 $\mathcal{B}({D}^{+}\ensuremath{\rightarrow}{e}^{+}\ensuremath{\nu})&lt;2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ which constrains new physics models.

Using $20.7\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data taken at $\sqrt{s}=3.671\text{ }\text{ }\mathrm{GeV}$ with the $\mathrm{CLEO}\mathrm{\text{\ensuremath{-}}}c$ detector, precision measurements of the electromagnetic form factors of the charged pion, charged kaon, and proton have been made for timelike momentum transfer of $|{Q}^{2}|=13.48\text{ }\text{ }{\mathrm{GeV}}^{2}$ by the reaction ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{h}^{+}{h}^{\ensuremath{-}}$. The measurements are the first ever with identified pions and kaons of $|{Q}^{2}|&gt;4\text{ }\text{ }{\mathrm{GeV}}^{2}$, with the results ${F}_{\ensuremath{\pi}}(13.48\text{ }\text{ }{\mathrm{GeV}}^{2})=0.075\ifmmode\pm\else\textpm\fi{}0.008(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.005(\mathrm{syst})$ and ${F}_{K}(13.48\text{ }\text{ }{\mathrm{GeV}}^{2})=0.063\ifmmode\pm\else\textpm\fi{}0.004(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.001(\mathrm{syst})$. The result for the proton, assuming ${G}_{E}^{p}={G}_{M}^{p}$, is ${G}_{M}^{p}(13.48\text{ }\text{ }{\mathrm{GeV}}^{2})=0.014\ifmmode\pm\else\textpm\fi{}0.002(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.001(\mathrm{syst})$, which is in agreement with earlier results.

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 ${\mathcal{F}}_{\ensuremath{-}}&gt;0.91$ at the 90% confidence level.

We measure the branching ratio of the purely leptonic decay of the D+ meson with unprecedented precision as B(D+ -> mu+ nu) = (3.82 +/- 0.32 +/- 0.09)x10^(-4), using 818/pb of data taken on the psi(3770) resonance with the CLEO-c detector at the CESR collider. We use this determination to derive a value for the pseudoscalar decay constant fD+, combining with measurements of the D+ lifetime and assuming |Vcd| = |Vus|. We find fD+ = (205.8 +/- 8.5 +/- 2.5) MeV. The decay rate asymmetry [B(D+ -> mu+ nu)-B(D- -> mu- nu)]/[B(D+ -> mu+ nu)+B(D- -> mu- nu)] = 0.08 +/- 0.08, consistent with no CP violation. We also set 90% confidence level upper limits on B(D+ -> tau+ nu) < 1.2x10^(-3) and B(D+ -> e+ nu) < 8.8x10^(-6).

In e(+)e(-) collisions using the CLEO detector, we have studied the decay of the D0 to the final state K(0)(S)pi(+)pi(-) with the initial flavor of the D0 tagged by the decay D(*+)-->D0pi(+). We use the Dalitz technique to measure the resonant substructure in this final state and clearly observe ten different contributions by fitting for their amplitudes and relative phases. We observe a K(*)(892)(+)pi(-) component which arises from doubly Cabibbo suppressed decays or D0-D0; mixing.

Based on a sample corresponding to 4.3 million produced tau-pair events, we have studied hadronic dynamics in the decay tau- --> nu_tau pi- pi0 pi0 in data recorded by the CLEO II detector operating at the CESR e+e- collider. The decay is dominated by the process tau --> nu_tau a_1(1260), with the a_1 meson decaying to three pions predominantly via the lowest dimensional (mainly S-wave) a_1 --> rho pi Born amplitude. From fits to the Dalitz plot and angular observables, we find significant additional contributions from amplitudes for a_1 decay to sigma pi, f_0(1370) pi and f_2(1270) pi, as well as higher dimensional a_1 --> rho pi and rho' pi amplitudes. The squared sigma pi amplitude accounts for ~15% of the total tau- --> nu_tau pi- pi0 pi0 rate in the models considered. We have searched for additional contributions from tau --> nu_tau pi'(1300). We place 90% confidence level upper limits on the branching fraction for this channel of between 1.0*10^{-4} and 1.9*10^{-4}, depending on the pi' decay mode. The pi- pi0 pi0 mass spectrum is parametrized by a Breit-Wigner form with a mass-dependent width which is specified according to the results of the Dalitz plot fits plus a coupling to an a_1 --> K* K amplitude. From a chi^2 fit, we extract the pole mass and width of the a_1, as well as the magnitude of the K* K coupling. We have also investigated the impact of a possible contribution from the a_1'(1700) meson on this spectrum. Finally, exploiting the parity-violating angular asymmetry in a_1 --> 3pi decay, we determine the signed value of the tau neutrino helicity to be h_{\nu_\tau} = -1.02 +- 0.13(stat.) +- 0.03(syst.+model), confirming the left-handedness of the tau neutrino.

Using 13.7 fb^{-1} of data recorded by the CLEO detector at CESR, we investigate the spectrum of charmed baryons which decay into Lambda_c^+ pi^- pi^+ and are more massive than the Lambda_{c1} baryons. We find evidence for two new states: one is broad and has an invariant mass roughly 480 MeV above that of the Lambda_c^+; the other is narrow with an invariant mass of 596 +- 1 +- 2 MeV above the Lambda_c^+ mass. These results are preliminary.

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).

In a sample of 19 million produced B mesons, we have observed the decays B -> eta K* and improved our previous measurements of B -> eta'K. The branching fractions we measure for these decay modes are BR(B+ -> eta K*+) = (26.4 +9.6-8.2 +- 3.3) x $10^{-6}$, BR(B0 -> eta K*0) = (13.8 +5.5-4.6 +- 1.6) x $10^{-6}$, BR(B+ -> eta' K+) = (80 +10-9 +- 7) x $10^{-6}$ and BR(B0 -> eta' K0) = (89 +18-16 +- 9) x $10^{-6}$. We have searched with comparable sensitivity for related decays and report upper limits for these branching fractions.

We report on the observation of the ηc′(2S01), the radial excitation of the ηc(1S01) ground state of charmonium, in the two-photon fusion reaction γγ→ηc′→KS0K±π∓ in 13.6 fb−1 of CLEO II/II.V data and 13.1 fb−1 of CLEO III data. We obtain M(ηc′)=3642.9±3.1(stat)±1.5(syst) MeV and M(ηc)=2981.8±1.3(stat)±1.5(syst) MeV. The corresponding values of hyperfine splittings between S01 and S13 states are ΔMhf(1S)=115.1±2.0 MeV and ΔMhf(2S)=43.1±3.4 MeV. Assuming that the ηc and ηc′ have equal branching fractions to KSKπ, we obtain Γγγ(ηc′)=1.3±0.6 keV.Received 23 December 2003DOI:https://doi.org/10.1103/PhysRevLett.92.142001©2004 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 $\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{+}{D}^{\ensuremath{-}})=(2.79\ifmmode\pm\else\textpm\fi{}{0.07}_{\ensuremath{-}0.04}^{+0.10})\text{ }\text{ }\mathrm{nb}$.

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 search for CP-violating charge asymmetries (alpha(CP)) in the B meson decays to K(+/-)pi(-/+), K(+/-)pi(0), K(0)(S)pi(+/-), K(+/-)eta('), and omega pi(+/-). Using 9.66 million upsilon(4S) decays collected with the CLEO detector, the statistical precision on alpha(CP) is in the range of +/-0.12 to +/-0.25 depending on decay mode. While CP-violating asymmetries of up to +/-0.5 are possible within the standard model, the measured asymmetries are consistent with zero in all five decay modes studied.

We report results of searches for charmless hadronic B meson decays to pseudoscalar( pi(+/-), K+/-, pi(0), or K(0)(S))-vector( rho, K(*), or omega) final states. By using 9.7x10(6) BB pairs collected with the CLEO detector, we report the first observation of B(-)--->pi(-)rho(0), B(0)-->pi(+/-)rho(-/+), and B(-)-->pi(-)omega, which are expected to be dominated by hadronic b-->u transitions. The measured branching fractions are (10.4(+3.3)(-3.4)+/-2.1)x10(-6), (27.6(+8.4)(-7.4)+/-4.2)x10(-6), and (11.3(+3.3)(-2.9)+/-1. 4)x10(-6), respectively. Branching fraction upper limits are set for all of the other decay modes investigated.

In a sample of $6.6\ifmmode\times\else\texttimes\fi{}{10}^{6}$ produced $B$ mesons we have observed decays $B\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}K$, with branching fractions $B({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{K}^{+})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({6.5}_{\ensuremath{-}1.4}^{+1.5}\ifmmode\pm\else\textpm\fi{}0.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ and $B({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{K}^{0})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({4.7}_{\ensuremath{-}2.0}^{+2.7}\ifmmode\pm\else\textpm\fi{}0.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. We have searched with comparable sensitivity for 17 related decays to final states containing an $\ensuremath{\eta}$ or ${\ensuremath{\eta}}^{\ensuremath{'}}$ meson accompanied by a single particle or low-lying resonance. Our upper limits for these constrain theoretical interpretations of the $B\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}K$ signal.

We have studied charmless hadronic decays of $B$ mesons into two-body final states with kaons and pions and observe three new processes with the following branching fractions: $B(B\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({4.3}_{\ensuremath{-}1.4}^{+1.6}\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, $B(B\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\pi}}^{0})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({14.6}_{\ensuremath{-}5.1\ensuremath{-}3.3}^{+5.9+2.4})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, and $B(B\ensuremath{\rightarrow}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{0})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({11.6}_{\ensuremath{-}2.7\ensuremath{-}1.3}^{+3.0+1.4})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. We also update our previous measurements for the decays $B\ensuremath{\rightarrow}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$ and ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$.

We have measured the first and second moments of the hadronic mass-squared distribution in B -> X_c l nu, for P(lepton) > 1.5 GeV/c. We find <M_X^2 - M_D[Bar]^2> = 0.251 +- 0.066 GeV^2, < (M_X^2 -<M_X^2>)^2 > = 0.576 +- 0.170 GeV^4, where M_D[Bar] is the spin-averaged D meson mass. From that first moment and the first moment of the photon energy spectrum in b -> s gamma, we find the HQET parameter lambda_1 (MS[Bar], to order 1/M^3 and beta_0 alpha_s^2) to be -0.24 +- 0.11 GeV^2. Using these first moments and the B semileptonic width, and assuming parton-hadron duality, we obtain |V_cb| = 0.0404 +- 0.0013.

We report a new measurement of the CKM parameter V_ub made with a sample of 9.7 million B B-bar events collected with the CLEO II detector. Using Heavy Quark theory, we combine the observed yield of leptons from semileptonic B decay in the end-point momentum interval 2.2-2.6 GeV/c with recent CLEO II data on B --> X_s gamma to find |V_ub| = (4.08 +/- 0.34 +/- 0.44 +/- 0.16 +/- 0.24) x 10^-3, where the first two uncertainties are experimental and the last two are from theory.

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 present the first evidence for the production of $\ensuremath{\Upsilon}(1D)$ states in the four-photon cascade, $\ensuremath{\Upsilon}(3S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{b}(2P),$ ${\ensuremath{\chi}}_{b}(2P)\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\Upsilon}(1D),$ $\ensuremath{\Upsilon}(1D)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{b}(1P),$ ${\ensuremath{\chi}}_{b}(1P)\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\Upsilon}(1S),$ followed by the $\ensuremath{\Upsilon}(1S)$ annihilation into ${e}^{+}{e}^{\ensuremath{-}}$ or ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}.$ The signal has a significance of 10.2 standard deviations. The measured product branching ratio for these five decays, $(2.5\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5},$ is consistent with the theoretical estimates. The data are dominated by the production of one $\ensuremath{\Upsilon}(1D)$ state consistent with the $J=2$ assignment. Its mass is determined to be $(10161.1\ifmmode\pm\else\textpm\fi{}0.6\ifmmode\pm\else\textpm\fi{}1.6)$ MeV, which is consistent with the predictions from potential models and lattice QCD calculations. We also searched for $\ensuremath{\Upsilon}(3S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{b}(2P),$ ${\ensuremath{\chi}}_{b}(2P)\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\Upsilon}(1D),$ followed by either $\ensuremath{\Upsilon}(1D)\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\Upsilon}(1S)$ or $\ensuremath{\Upsilon}(1D)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(1S).$ We find no evidence for such decays and set upper limits on the product branching ratios.

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.

Using the CLEO detector at the Cornell Electron-positron Storage Ring, we have measured the scaled momentum spectra, $d\ensuremath{\sigma}/d{x}_{p}$, and the inclusive production cross sections of the charm mesons ${D}^{+}$, ${D}^{0}$, ${D}^{\ensuremath{\star}+}$, and ${D}^{\ensuremath{\star}0}$ in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at about 10.5 GeV center of mass energy, excluding the decay products of $B$ mesons. The statistical accuracy and momentum resolution are superior to previous measurements at this energy.

The spin-singlet $P$-wave state of charmonium, ${h}_{c}{(}^{1}{P}_{1})$, has been observed in the decay $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{h}_{c}$ followed by ${h}_{c}\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c}$. Inclusive and exclusive analyses of the $M({h}_{c})$ spectrum have been performed. Two complementary inclusive analyses select either a range of energies for the photon emitted in ${h}_{c}\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c}$ or a range of values of $M({\ensuremath{\eta}}_{c})$. These analyses, consistent with one another within statistics, yield $M({h}_{c})=[3524.9\ifmmode\pm\else\textpm\fi{}0.7\text{ }\text{ }(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.4\text{ }\text{ }(\mathrm{sys})]\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and a product of the branching ratios ${\mathcal{B}}_{\ensuremath{\psi}}(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{h}_{c})\ifmmode\times\else\texttimes\fi{}{\mathcal{B}}_{h}({h}_{c}\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\eta}}_{c})=[3.5\ifmmode\pm\else\textpm\fi{}1.0\text{ }\text{ }(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.7\text{ }\text{ }(\mathrm{sys})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. When the ${\ensuremath{\eta}}_{c}$ is reconstructed in seven exclusive decay modes, $17.5\ifmmode\pm\else\textpm\fi{}4.5$ ${h}_{c}$ events are seen with an average mass $M({h}_{c})=[3523.6\ifmmode\pm\else\textpm\fi{}0.9\text{ }\text{ }(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.5\text{ }\text{ }(\mathrm{sys})]\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, and ${\mathcal{B}}_{\ensuremath{\psi}}{\mathcal{B}}_{h}=[5.3\ifmmode\pm\else\textpm\fi{}1.5\text{ }\text{ }(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.0\text{ }\text{ }(\mathrm{sys})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. If combined, the inclusive and exclusive data samples yield an overall mass $M({h}_{c})=[3524.4\ifmmode\pm\else\textpm\fi{}0.6\text{ }\text{ }(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.4\text{ }\text{ }(\mathrm{sys})]\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ and product of branching ratios ${\mathcal{B}}_{\ensuremath{\psi}}{\mathcal{B}}_{h}=[4.0\ifmmode\pm\else\textpm\fi{}0.8\text{ }\text{ }(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.7\text{ }\text{ }(\mathrm{sys})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. The ${h}_{c}$ mass implies a $P$-wave hyperfine splitting $\ensuremath{\Delta}{M}_{\mathrm{HF}}(1P)\ensuremath{\equiv}⟨M({1}^{3}P)⟩\ensuremath{-}M({1}^{1}{P}_{1})=[1.0\ifmmode\pm\else\textpm\fi{}0.6\text{ }\text{ }(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.4\text{ }\text{ }(\mathrm{sys})]\text{ }\text{ }\mathrm{MeV}/{c}^{2}$.

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.

A precision measurement of the D0 meson mass has been made using ∼281 pb−1 of e+e− annihilation data taken with the CLEO-c detector at the ψ(3770) resonance. The exclusive decay D0→KSϕ has been used to obtain M(D0)=1864.847±0.150(stat)±0.095(syst) MeV. This corresponds to M(D0¯¯¯D*0)=3871.81±0.36 MeV, and leads to a well-constrained determination of the binding energy of the proposed D0¯¯¯D*0 molecule X(3872), as Eb=0.6±0.6 MeV.Received 8 January 2007DOI:https://doi.org/10.1103/PhysRevLett.98.092002©2007 American Physical Society

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 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

Using a sample of 3.3×106 Υ(4S)→B¯B events collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR), we measure B(→Bρlν), |Vub|, and the partial rate (ΔΓ) in three bins of q2≡(pB−pρ)2. We find B(B0→ρ−l+ν)=(2.69±0.41+0.35−0.40±0.50)×10−4, |Vub|=(3.23±0.24+0.23−0.26±0.58)×10−3, ΔΓ(0<q2<7GeV2/c4)=(7.6±3.0+0.9−1.2±3.0)×10−2ns−1, ΔΓ(7<q2<14GeV2/c4)=(4.8±2.9+0.7−0.8±0.7)×10−2ns−1, and ΔΓ(14<q2<21GeV2/c4)=(7.1±2.1+0.9−1.1±0.6)×10−2ns−1. Here, l=e or μ, but not both, and the errors are statistical, systematic, and theoretical. The method is sensitive primarily to →Bρlν decays with leptons in the energy range above 2.3 GeV. Averaging with the previously published CLEO results for →Bρlν, we obtain B(B0→ρ−l+ν)=(2.57±0.29+0.33−0.46±0.41)×10−4 and |Vub|=(3.25±0.14+0.21−0.29±0.55)×10−3. Received 24 May 1999DOI:https://doi.org/10.1103/PhysRevD.61.052001©2000 American Physical Society

We have studied two-body charmless hadronic decays of B mesons into the final states straight phiK and phiK(*). Using 9.7 million B&Bmacr; pairs collected with the CLEO II detector, we observe the decays B- --> phiK- and B0--> phiK(*0) with the following branching fractions: B(B--->phiK-) = (5.5(+2.1)(-1.8)+/-0.6)x10(-6) and B(B0--> phiK(*0)) = (11.5(+4.5+1.8)(-3.7-1.7))x10(-6). We also see evidence for the decays B0-->phiK0 and B---> phiK(*-). However, since the statistical significance is not overwhelming for these modes, we determine upper limits of <12.3x10(-6) and <22.5x10(-6) ( 90% confidence level), respectively.

We describe several measurements using the decays D 0 → K + K -and π + π -.We find the ratio of partial widths, Γ D 0 → K + K -/Γ D 0 → π + π -, to be 2.96 ± 0.16 ± 0.15, where the first error is statistical and the second is systematic.We observe no evidence for direct CP violation, obtaining A CP (KK) = (0.0 ± 2.2 ± 0.8)% and A CP (ππ) = (1.9 ± 3.2 ± 0.8)%.In the limit of no CP violation we measure the mixing parameter y CP = -0.012± 0.025 ± 0.

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

We have measured the CP asymmetry A(CP) identical with[gamma(b-->sgamma)-gammab-->sgamma)]/[gamma(b-->sgamma)+gamma(b-->sgamma)] to be A(CP) = (-0.079+/-0.108+/-0.022) (1.0+/-0.030), implying that, at 90% confidence level, A(CP) lies between -0.27 and +0.10. These limits rule out some extreme non-standard-model predictions, but are consistent with most, as well as with the standard model.

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.

We have studied the inclusive photon spectrum in psi(2S) decays using the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates for psi(2S)--> gamma chicJ(1P) (J=0,1,2). We also confirm the hindered magnetic dipole (M1) transition, psi(2S)-->gamma etac(1S). However, the direct M1 transition psi(2S)-->gamma etac(2S) observed by the Crystal Ball as a narrow peak at a photon energy of 91 MeV is not found in our data.

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.

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%.

Using data recorded by the CLEO II detector at CESR, we report evidence for two new charmed baryons, one decaying into $\Xi_c^+\pi^+\pi^-$ via an intermediate $\Xi_c^{*0}$, and its isospin partner decaying into $\Xi_c^0\pi^+\pi^-$ via an intermediate $\Xi_c^{*+}$. We measure the mass differences of the two states to be $M(\Xi_c^+\pi^+\pi^-)-M(\Xi_c^+)=$ $348.6\pm0.6\pm1.0$ MeV, and $M(\Xi_c^0\pi^+\pi^-)-M(\Xi_c^0)=$ $347.2\pm0.7\pm2.0$ MeV. We interpret these new states as the $J^P = {3 \over{2}}^- $ $\Xi_{c1}$ particles, the charmed-strange analogues of the $\Lambda_{c1}^+(2625)$.

Using a sample of 3.3 million B-meson decays collected with the CLEO detector at the Cornell Electron Storage Ring, we have studied $B^- \to D^0 \ell\nu$ and $\bar{B}^0 \to D^+ \ell\nu$ decays, where $\ell$ can be either an electron or muon. We distinguish $B \to D \ell\nu$ from other B semileptonic decays by examining the net momentum and energy of the particles recoiling against the D-lepton pairs. We find the decay rate $\Gamma(B \to D\ell\nu)$ = (14.1 +- 1.0 +- 1.2) ns-1 and derive branching fractions for $B^- \to D^0 \ell\nu$ and $\bar{B^0} \to D^+ \ell\nu$ of (2.32 +- 0.17 +- 0.20)% and 2.20 +- 0.16 +- 0.19)% respectively, where the uncertainties are statistical and systematic. We also investigate the $B \to D \ell\nu$ form factor and the implication of the result for $|V_{cb}|$.

We have studied the color-suppressed hadronic decays of neutral B mesons into the final states ${D}^{(*)0}{\ensuremath{\pi}}^{0}$. Using $9.67\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected with the CLEO detector, we observe the decays ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{0}$ and ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{*0}{\ensuremath{\pi}}^{0}$ with the branching fractions $B({\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{0})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({2.74}_{\ensuremath{-}0.32}^{+0.36}\ifmmode\pm\else\textpm\fi{}0.55)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and $B({\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{*0}{\ensuremath{\pi}}^{0})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({2.20}_{\ensuremath{-}0.52}^{+0.59}\ifmmode\pm\else\textpm\fi{}0.79)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. The first error is statistical and the second systematic. The statistical significance of the ${D}^{0}{\ensuremath{\pi}}^{0}$ signal is $12.1\ensuremath{\sigma}$ ( $5.9\ensuremath{\sigma}$ for ${D}^{*0}{\ensuremath{\pi}}^{0}$). Utilizing the ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{(*)0}{\ensuremath{\pi}}^{0}$ branching fractions we determine the strong phases ${\ensuremath{\delta}}_{I,D(*)}$ between isospin $1/2$ and $3/2$ amplitudes in the $D\ensuremath{\pi}$ and ${D}^{*}\ensuremath{\pi}$ final states to be $\mathrm{cos}{\ensuremath{\delta}}_{I,D}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.89\ifmmode\pm\else\textpm\fi{}0.08$ and $\mathrm{cos}{\ensuremath{\delta}}_{I,D*}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.89\ifmmode\pm\else\textpm\fi{}0.08$, respectively.

From electron-positron collision data collected with the CLEO detector operating at Cornell Electron Storage Ring near sqrt[s]=10.6 GeV, improved measurements of the branching fractions for tau decays into three explicitly identified hadrons and a neutrino are presented as B(tau(-)-->pi(-)pi(+)pi(-)nu(tau))=(9.13+/-0.05+/-0.46)%, B(tau(-)-->K-pi(+)pi(-)nu(tau))=(3.84+/-0.14+/-0.38) x 10(-3), B(tau(-)-->K-K+pi(-)nu(tau))=(1.55+/-0.06+/-0.09) x 10(-3), and B(tau(-)-->K-K+K-nu(tau))<3.7 x 10(-5) at 90% C.L., where the uncertainties are statistical and systematic, respectively.

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

We present a measurement of the composition of B meson inclusive semileptonic decays using 9.4 ${\mathrm{fb}}^{\mathrm{\ensuremath{-}}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ data taken with the CLEO detector at the $\ensuremath{\Upsilon}(4S)$ resonance. In addition to measuring the charged lepton kinematics, the neutrino four-vector is inferred using the hermiticity of the detector. We perform a maximum likelihood fit over the full three-dimensional differential decay distribution for the fractional contributions from the $\stackrel{\ensuremath{\rightarrow}}{B}{X}_{c}\mathcal{l}\ensuremath{\nu}$ processes with ${X}_{c}=D,$ ${D}^{*},$ ${D}^{**},$ and nonresonant ${X}_{c},$ and the process $\stackrel{\ensuremath{\rightarrow}}{B}{X}_{u}\mathcal{l}\ensuremath{\nu}.$ From the fit results we extract the first and second moments of the ${M}_{X}^{2}$ and ${q}^{2}$ distributions with minimum lepton-energy requirements of 1.0 GeV and 1.5 GeV. We find $〈{M}_{X}^{2}\ensuremath{-}{M}_{D}^{2}〉=(0.456\ifmmode\pm\else\textpm\fi{}0.014\ifmmode\pm\else\textpm\fi{}0.045\ifmmode\pm\else\textpm\fi{}0.109){\mathrm{GeV}}^{2}{/c}^{4}$ with a minimum lepton energy of 1.0 GeV and $〈{M}_{X}^{2}\ensuremath{-}{M}_{D}^{2}〉=(0.293\ifmmode\pm\else\textpm\fi{}0.012\ifmmode\pm\else\textpm\fi{}0.033\ifmmode\pm\else\textpm\fi{}0.048){\mathrm{GeV}}^{2}{/c}^{4}$ with minimum lepton energy of 1.5 GeV. The uncertainties are from statistics, detector systematic effects, and model dependence, respectively. As a test of the HQET and OPE calculations, the results for the ${M}_{X}^{2}$ moment as a function of the minimum lepton energy requirement are compared to the predictions.

Using $3.08\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\psi}(2S)$ decays observed in ${e}^{+}{e}^{\ensuremath{-}}$ collisions by the CLEO detector, we present the results of a study of the $\ensuremath{\psi}(2S)$ decaying into baryon-antibaryon final states. We report the most precise measurements of the following eight modes: $p\overline{p}$, $\ensuremath{\Lambda}\overline{\ensuremath{\Lambda}}$, ${\ensuremath{\Sigma}}^{+}\overline{{\ensuremath{\Sigma}}^{+}}$ (first observation), ${\ensuremath{\Sigma}}^{0}\overline{{\ensuremath{\Sigma}}^{0}}$, ${\ensuremath{\Xi}}^{\ensuremath{-}}\overline{{\ensuremath{\Xi}}^{\ensuremath{-}}}$, and ${\ensuremath{\Xi}}^{0}\overline{{\ensuremath{\Xi}}^{0}}$ (first observation), and place upper limits for the modes $\ensuremath{\Xi}(1530{)}^{0}\overline{\ensuremath{\Xi}(1530{)}^{0}}$ and ${\ensuremath{\Omega}}^{\ensuremath{-}}\overline{{\ensuremath{\Omega}}^{\ensuremath{-}}}$.

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

From e(+)e(-) collision data acquired with the CLEO detector at the Cornell Electron Storage Ring, we observe the non-DD(_) decay Psi(3770))-->gammachi(c1) with a statistical significance of 6.6 standard deviations, using the two-photon cascades to J/Psi and J/Psi-->l(+)l(-). We determine sigma(e(=)e(-)-->Psi(3770))xBeta(Psi(3770)-->gammachi(c1))=(18.0 +/- 3.3 +/- 2.5) pb and branching fraction Beta(Psi(3770)-->gammachi(c1)=(2.8 +/- 0.5+/-0.4) x 10(-3). We set 90% C.L. upper limits for the transition to chi(c2) (chi(c0)): sigma x Beta<5.7 pb (<282 pb) and Beta<0.9 x 10(-3) (<44 x 10(-3)). We also determine Gamma(Psi(3770)gammachi(c1))/Gamma(Psi(3770)-->pi(+)pi(-)J/Psi)=1.5 +/- 0.3 +/- 0.3 (>1.0 at 90% C.L.), which bears upon the interpretation of X(3872).

We have studied the Cabibbo-suppressed decay mode D^0 into K^+ K^- pi^0 using a Dalitz plot technique and find the strong phase difference delta_D [defined as delta_(K*^- K^+) - delta_(K*^+ K^-)] = 332 degrees +- 8 degrees +- 11 degrees and relative amplitude r_D [defined as a_(K*^- K^+) / a_(K*^+ K^-)] = 0.52 +- 0.05 +- 0.04. This measurement indicates significant destructive interference between D^0 into K^+ (K^- pi^0)_K*^- and D^0 into K^- (K^+ pi^0)_K*^+ in the Dalitz plot region where these two modes overlap. This analysis uses 9.0 fb^(-1) of data collected at s^(1/2) of approximately 10.58 GeV with the CLEO III detector.

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

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 report the first observation of two narrow charmed strange baryons decaying to $\Xi_c^+\gamma$ and $\Xi_c^0\gamma$, respectively, using data from the CLEO II detector at CESR. We interpret the observed signals as the $\Xi_c^{+\prime}(c{su})$ and $\Xi_c^{0\prime}(c{sd})$, the symmetric partners of the well-established antisymmetric $\Xi_c^+(c[su])$ and $\Xi_c^0(c[sd])$. The mass differences $M(\Xi_c^{+\prime})-M(\Xi_c^+)$ and $M(\Xi_c^{0\prime})-M(\Xi_c^0)$ are measured to be $107.8\pm 1.7\pm 2.5$ and $107.0\pm 1.4\pm 2.5 MeV/c^2$, respectively.

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.

We analyze 9.7 x 10^6 B\bar{B}$ pairs recorded with the CLEO detector to determine the production ratio of charged to neutral B-meson pairs produced at the Y(4S) resonance. We measure the rates for B^0 -> J/psi K^{(*)0} and B^+ -> J/psi K^{(*)+} decays and use the world-average B-meson lifetime ratio to extract the relative widths f+-/f00 = Gamma(Y(4S) -> B+B-)/Gamma(Y(4S) -> B0\bar{B0}) = = 1.04 +/- 0.07(stat) +/- 0.04(syst). With the assumption that f+- + f00 = 1, we obtain f00 = 0.49 +/- 0.02(stat) +/- 0.01(syst) and f+- = 0.51 +/- 0.02(stat) +/- 0.01(syst). This production ratio and its uncertainty apply to all exclusive B-meson branching fractions measured at the Y(4S) resonance.

We report a new measurement of the B-meson semileptonic decay momentum spectrum that has been made with a sample of 9.4 fb−1 of e+e− data collected with the CLEO II detector at the Υ(4S) resonance. Electrons from primary semileptonic decays and secondary charm decays were separated by using charge and angular correlations in Υ(4S) events with a high-momentum lepton and an additional electron. We determined the semileptonic branching fraction to be B(→BXe+νe)=(10.91±0.09±0.24)% from the normalization of the electron-energy spectrum. We also measured the moments of the electron-energy spectrum with minimum energies from 0.6 to 1.5 GeV.Received 8 April 2004DOI:https://doi.org/10.1103/PhysRevD.70.032003©2004 American Physical Society

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 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.

Using 9.0 fb -1 of integrated luminosity in e + e -collisions near the Υ(4S) mass collected with the CLEO II.V detector we report the first observation of the decay D 0 → K 0 S ηπ 0 .We measure the ratio of branching fractions, BR(D 0 →K 0 S ηπ 0 ) BR(D 0 →K 0 S π 0 ) = 0.46 ± 0.07 ± 0.06.We perform a Dalitz analysis of 155 selected D 0 → K 0 S ηπ 0 candidates and find leading contributions from a 0 (980)K 0 S and K * (892)η intermediate states.

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

Using of data collected with the CLEO-c detector, we report on first observations and measurements of Cabibbo-suppressed decays of D mesons in the following six decay modes: pi+ pi- pi0 pi0, pi+ pi+ pi- pi- pi0, pi+ pi0 pi0, pi+ pi+ pi- pi0, eta pi0, and omega pi+ pi-. Improved branching fraction measurements in eight other multipion decay modes are also presented. The measured D --> pi pi rates allow us to extract the ratio of isospin amplitudes A(DeltaI = (3/2) / A(DeltaI = (1/2)) = 0.420 +/- 0.014(stat) +/- 0.016(syst) and the strong phase shift of delta1 = (86.4 +/- 2.8 +/- 3.3) degrees, which is quite large and now more precisely determined.

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