B. Moziak

Model-independent determination of the strong-phase difference between D0 and D⊃̄0→KS,L0h+h- (h=π, K) and its impact on the measurement of the CKM angle γ/Φ3

We report the first determination of the relative strong-phase difference between D0→KS,L0K+K- and D 0→KS,L0K+K-. In addition, we present updated measurements of the relative strong-phase difference between D0→KS,L0π+π- and D 0→KS,L0π+π-. Both measurements exploit the quantum coherence between a pair of D0 and D 0 mesons produced from ψ(3770) decays. The strong-phase differences measured are important for determining the Cabibbo-Kobayashi-Maskawa angle γ/ϕ3 in B-→K-D˜0 decays, where D˜0 is a D0 or D 0 meson decaying to KS0h+h- (h=π, K), in a manner independent of the model assumed to describe the D0→KS0h+h- decay. Using our results, the uncertainty in γ/ϕ3 due to the error on the strong-phase difference is expected to be between 1.7° and 3.9° for an analysis using B-→K-D˜0, D˜0→KS0π+π- decays, and between 3.2° and 3.9° for an analysis based on B-→K-D˜0, D˜0→KS0K+K- decays. A measurement is also presented of the CP-odd fraction, F-, of the decay D0→KS0K+K- in the region of the ϕ→K+K- resonance. We find that in a region within 0.01  GeV2/c4 of the nominal ϕ mass squared F->0.91 at the 90% confidence level.

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.

Measurements of D meson decays to two pseudoscalar mesons

Using data collected on the {psi}(3770) resonance and near the D{sub s}*{sup {+-}D}{sub s}{sup {+-}}peak production energy by the CLEO-c detector, we study the decays of the possible D{yields}PP modes and report measurements of or upper limits on all branching fractions for Cabibbo-favored, singly Cabibbo-suppressed, and doubly Cabibbo-suppressed D{yields}PP decays except modes involving K{sub L}{sup 0} (and except D{sup 0{yields}}K{sup +{pi}-}). We normalize with respect to the Cabibbo-favored D modes, D{sup 0{yields}}K{sup -{pi}+}, D{sup +{yields}}K{sup -{pi}+{pi}+}, and D{sub s}{sup +{yields}}K{sup +}K{sub S}{sup 0}.

Measurement of the ηb(1S) mass and the branching fraction for Υ(3S)→γηb(1S)

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.

Observation of the hc(1P) Using e+e- Collisions above the DD̄ Threshold

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.

Transverse momentum dependence of semi-inclusive pion production

Abstract Cross sections for semi-inclusive electroproduction of charged pions ( π ± ) from both proton and deuteron targets were measured for 0.2 x 0.5 , 2 Q 2 4 GeV 2 , 0.3 z 1 , and P t 2 0.2 GeV 2 . For P t 0.1 GeV , we find the azimuthal dependence to be small, as expected theoretically. For both π + and π − , the P t dependence from the deuteron is found to be slightly weaker than from the proton. In the context of a simple model, this implies that the initial transverse momenta width of d quarks is larger than for u quarks and, contrary to expectations, the transverse momentum width of the favored fragmentation function is larger than the unfavored one.

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.

Semi-Inclusive Charged-Pion Electroproduction off Protons and Deuterons: Cross Sections, Ratios and Access to the Quark-Parton Model at Low Energies

A large set of cross sections for semi-inclusive electroproduction of charged pions (π^±) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared W^2>4 GeV^2 (up to ≈7 GeV^2) and range in four-momentum transfer squared 2<Q^2<4 (GeV/c)^2, and cover a range in the Bjorken scaling variable 0.2<x<0.6. The fractional energy of the pions spans a range 0.3<z<1, with small transverse momenta with respect to the virtual-photon direction, Pt^(2)_(t)<0.2 (GeV/c)2. The invariant mass that goes undetected, M_x or W′, is in the nucleon resonance region, W′<2 GeV. The new data conclusively show the onset of quark-hadron duality in this process, and the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark→pion production mechanisms. The x, z, and Pt^(2)_(t) dependences of several ratios (the ratios of favored-unfavored fragmentation functions, charged pion ratios, deuteron-hydrogen and aluminum-deuteron ratios for π^+ and π^−) have been studied. The ratios are found to be in good agreement with expectations based upon a high-energy quark-parton model description. We find the azimuthal dependences to be small, as compared to exclusive pion electroproduction, and consistent with theoretical expectations based on tree-level factorization in terms of transverse-momentum-dependent parton distribution and fragmentation functions. In the context of a simple model, the initial transverse momenta of d quarks are found to be slightly smaller than for u quarks, while the transverse momentum width of the favored fragmentation function is about the same as for the unfavored one, and both fragmentation widths are larger than the quark widths.

Study of ψ(2S) decays to γpp̄, π0pp̄, and ηpp̄, and search for pp̄ threshold enhancements

The decays of {psi}(2S) into {gamma}pp, {pi}{sup 0}pp, and {eta}pp have been studied with the CLEO-c detector using a sample of 24.5x10{sup 6} {psi}(2S) events obtained from e{sup +}e{sup -} annihilations at {radical}(s)=3686 MeV. The data show evidence for the excitation of several N{sup *} resonances in p{pi}{sup 0} and p{eta} channels in {pi}{sup 0}pp and {eta}pp decays, and f{sub 2} states in {gamma}pp decay. Branching fractions for decays of {psi}(2S) to {gamma}pp, {pi}{sup 0}pp, and {eta}pp have been determined. No evidence for pp threshold enhancements was found in the reactions {psi}(2S){yields}Xpp, where X={gamma}, {pi}{sup 0}, {eta}. We do, however, find confirming evidence for a pp threshold enhancement in J/{psi}{yields}{gamma}pp as previously reported by BES.

Onset of Quark-Hadron Duality in Pion Electroproduction

A large data set of charged-pion (pi+/-) electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-->pion production mechanisms.