A. W. Scott

Improved measurements of D meson semileptonic decays to π and K mesons

Using the entire CLEO-c {psi}(3770){yields}DD event sample, corresponding to an integrated luminosity of 818 pb{sup -1} and approximately 5.4x10{sup 6} DD events, we present a study of the decays D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e}, D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e}, D{sup +}{yields}{pi}{sup 0}e{sup +}{nu}{sub e}, and D{sup +}{yields}K{sup 0}e{sup +}{nu}{sub e}. 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 q{sup 2} bins. We fit these rates using several form factor parametrizations and report the results, including form factor shape parameters and the branching fractions B(D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e})=(0.288{+-}0.008{+-}0.003)%, B(D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e})=(3.50{+-}0.03{+-}0.04)%, B(D{sup +}{yields}{pi}{sup 0}e{sup +}{nu}{sub e})=(0.405{+-}0.016{+-}0.009)%, and B(D{sup +}{yields}K{sup 0}e{sup +}{nu}{sub e})=(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 |V{sub cd}|=0.234{+-}0.007{+-}0.002{+-}0.025 and |V{sub cs}|=0.985{+-}0.009{+-}0.006{+-}0.103, where the third uncertainties are from lattice quantum chromodynamics.

Dalitz plot analysis of Ds+→K+K-π+

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 perform a Dalitz plot analysis of about 100 000 Ds+ decays to K+K-π+ 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+π- 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.

Search for D0→p̄e+ and D0→pe-

We search for simultaneous baryon and lepton number violating decays of the D 0 meson. Specifically, we use 281 pb ―1 of data taken on the ψ(3770) resonance with the CLEO-c detector at the CESR collider to look for decays D 0 → pe + , D 0 → pe + , D 0 → pe ― , and D 0 → pe ― . We find no significant signals and set the following branching fraction upper limits: D 0 → pe + (D 0 → pe + ) < 1.1 × 10 ―5 and D 0 → pe ― (D 0 → pe ― ) < 1.0 × 10 ―5 , both at the 90% confidence level.

Measurement of the decay rate of Ξc 0→pK -K-π+ relative to Ξc 0→Ξ-π+

Using the CLEO IIIdetector at CESR, we have measured the branching ratio of the decay [Formula Presented] relative to [Formula Presented] We find [Formula Presented] In the resonant substructure of this mode, we find evidence for [Formula Presented] decays to [Formula Presented] and measure [Formula Presented] and [Formula Presented] for the [Formula Presented] decays.

Search for D{sup 0}{yields}pe{sup +} and D{sup 0}{yields}pe{sup -}

We search for simultaneous baryon and lepton number violating decays of the D{sup 0} meson. Specifically, we use 281 pb{sup -1} of data taken on the {psi}(3770) resonance with the CLEO-c detector at the CESR collider to look for decays D{sup 0}{yields}pe{sup +}, D{sup 0}{yields}pe{sup +}, D{sup 0}{yields}pe{sup -}, and D{sup 0}{yields}pe{sup -}. We find no significant signals and set the following branching fraction upper limits: D{sup 0}{yields}pe{sup +}(D{sup 0}{yields}pe{sup +})<1.1x10{sup -5} and D{sup 0}{yields}pe{sup -}(D{sup 0}{yields}pe{sup -})<1.0x10{sup -5}, both at the 90% confidence level.

Dalitz plot analysis of D{sub s}{sup +}{yields}K{sup +}K{sup -}{pi}{sup +}

We perform a Dalitz plot analysis of the decay D{sub s}{sup +}{yields}K{sup +}K{sup -}{pi}{sup +} with the CLEO-c data set of 586 pb{sup -1} of e{sup +}e{sup -} collisions accumulated at {radical}(s)=4.17 GeV. This corresponds to about 0.57x10{sup 6} D{sub s}{sup {+-}}D{sub s}*{sup {+-}} 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{sub 0}(1370){pi}{sup +} contribution. We measure the magnitude, phase, and fit fraction of K*(892){sup 0}K{sup +}, {phi}(1020){pi}{sup +}, K{sub 0}{sup *}(1430)K{sup +}, f{sub 0}(980){pi}{sup +}, f{sub 0}(1710){pi}{sup +}, and f{sub 0}(1370){pi}{sup +} contributions and limit the possible contributions of other KK and K{pi} resonances that could appear in this decay.

Determination of the D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup 0} and D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} coherence factors and average strong-phase differences using quantum-correlated measurements

The first measurements of the coherence factors (R{sub K{pi}}{sub {pi}{sup 0}} and R{sub K3{pi}}) and the average strong-phase differences ({delta}{sub D}{sup K{pi}}{sup {pi}{sup 0}} and {delta}{sub D}{sup K3{pi}}) for D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup 0} and D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} are presented. These parameters can be used to improve the determination of the unitarity triangle angle {gamma} in B{sup -}{yields}DK{sup -} decays, where D is a D{sup 0} or D{sup 0} meson decaying to the same final state. The measurements are made using quantum-correlated, fully reconstructed D{sup 0}D{sup 0} pairs produced in e{sup +}e{sup -} collisions at the {psi}(3770) resonance. The measured values are: R{sub K{pi}}{sub {pi}{sup 0}}=0.84{+-}0.07, {delta}{sub D}{sup K{pi}}{sup {pi}{sup 0}}=(227{sub -17}{sup +14}) deg., R{sub K3{pi}}=0.33{sub -0.23}{sup +0.20}, and {delta}{sub D}{sup K3{pi}}=(114{sub -23}{sup +26}) deg. These results indicate significant coherence in the decay D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup 0}, whereas lower coherence is observed in the decay D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -}. The analysis also results in a small improvement in the knowledge of other D-meson parameters, in particular, the strong-phase difference for D{sup 0}{yields}K{sup -}{pi}{sup +}, {delta}{sub D}{sup K{pi}}, and the mixing parameter y.

Study of the Decays D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e}, D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e}, D{sup +}{yields}{pi}{sup 0}e{sup +}{nu}{sub e}, and D{sup +}{yields}K{sup 0}e{sup +}{nu}{sub e}

By using 1.8x10{sup 6} DD pairs, we have measured B(D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e})=0.299(11)(9)%, B(D{sup +}{yields}{pi}{sup 0}e{sup +}{nu}{sub e})=0.373(22)(13)%, B(D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e})=3.56(3)(9)%, and B(D{sup +}{yields}K{sup 0}e{sup +}{nu}{sub e})=8.53(13)(23)% and have studied the q{sup 2} dependence of the form factors. By combining our results with recent lattice calculations, we obtain |V{sub cd}|=0.217(9)(4)(23) and |V{sub cs}|=1.015(10)(11)(106)

Radiative decays of the {upsilon}(1S) to {gamma}{pi}{sup 0}{pi}{sup 0}, {gamma}{eta}{eta} and {gamma}{pi}{sup 0}{eta}

We report on a study of exclusive radiative decays of the Υ(1S) resonance into the final states γπ0π0, γηη and γπ0η, using 1.13 fb−1 of e+e− annihilation data collected at √ s = 9.46GeV with the CLEO III detector operating at the Cornell Electron Storage Ring. In the channel γπ0π0, we measure the branching ratio for the decay mode Υ(1S) → γf2(1270) to be (10.5 ± 1.6 (stat) +1.9 −1.8 (syst)) × 10−5. We place upper limits on the product branching ratios for the isoscalar resonances f0(1500) and f0(1710) for the π 0π0 and ηη decay channels. We also set an upper limit on the Υ(1S) radiative decay into π0η. PACS numbers: 13.20.Gd, 12.39.Mk

Measurement of B(D{sub s}{sup +}{yields}l{sup +}{nu}) and the decay constant f{sub D{sub S}{sup +}}

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