Measurement of the η′-meson mass using J/ ψ→γη′
Physical Review Letters 101:18 (2008)
Abstract:
We measure the mass of the η′ meson using ψ(2S) →π+π-J/ψ, J/ψ→γη′ events acquired with the CLEO-c detector operating at the CESR e+e- collider. Using three decay modes, η′→ρ0γ, η′→π+π-η with η→γγ, and η′→π+π-η with η→π+π-π0, we find Mη′=957.793±0.054±0. 036MeV, in which the uncertainties are statistical and systematic, respectively. This result is consistent with but substantially more precise than the current world average. © 2008 The American Physical Society.Search for very light CP-odd Higgs boson in radiative decays of Υ(1S)
Physical Review Letters 101:15 (2008)
Abstract:
We search for a non-SM-like CP-odd Higgs boson (a10) decaying to τ+τ- or μ+μ- in radiative decays of the Υ(1S). No significant signal is found, and upper limits on the product branching ratios are set. Our τ+τ- results are almost 2 orders of magnitude more stringent than previous upper limits. Our data provide no evidence for a Higgs state with a mass of 214 MeV decaying to μ+μ-, previously proposed as an explanation for 3 Σ+→pμ+μ- events observed by the HyperCP experiment. Our results constrain NMSSM models. © 2008 The American Physical Society.Search for CP violation in the Dalitz-plot analysis of D±→K+K- π±
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:7 (2008)
Abstract:
We report on a search for CP asymmetry in the singly Cabibbo-suppressed decay D+→K+K-π+ using a data sample of 818pb-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)%. © 2008 The American Physical Society.Observation of χcJ radiative decays to light vector mesons
Physical Review Letters 101:15 (2008)
Abstract:
Using a total of 2.74×107 decays of the ψ(2S) collected with the CLEO-c detector, we present a study of χcJ→γV, where V=ρ0, ω, □. The transitions χc1→γρ0 and χc1→γω are observed with B(χc1→γρ0)=(2. 43±0.19±0.22)×10-4 and B(χc1→γω)=(8. 3±1.5±1.2)×10-5. In the χc1→γρ0 transition, the final state meson is dominantly longitudinally polarized. Upper limits on the branching fractions of other χcJ states to light vector mesons are presented. © 2008 The American Physical Society.Precision measurement of B(D+→μ+ν) and the pseudoscalar decay constant fD+
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:5 (2008)