Search for decays of B0 mesons into pairs of leptons: B0↑e+e-, B0→μ+μ-, and B0→e±μ∓
Physical Review D - Particles, Fields, Gravitation and Cosmology 62:9 (2000) 1-5
Abstract:
We search for the decay of the B0 meson into a pair of leptons in the suppressed channels B0→e+e-, B0→μ+μ- and in the lepton number violating channel B0→e±μ∓ in a sample of 9.7×106 BB̄ pairs recorded by CLEO detector. No signal is found, and the following upper limits on the branching fractions are established: B(B0→e+e-)<8.3×10-7, B(B0→μ+μ-)<6.1×10 -7, B(B0→e±μ ∓)<15×10-7 at 90% confidence level. A new lower limit on the Pati-Salam leptoquark mass MLQ>27 TeV is established at 90% confidence level. © 2000 The American Physical Society.Measurements of the mass, total width, and two-photon partial width of the eta(c) meson.
Phys Rev Lett 85:15 (2000) 3095-3099
Abstract:
Using 13.4 fb(-1) of data collected with the CLEO detector at the Cornell Electron Storage Ring, we have observed 300 events for the two-photon production of ground-state pseudoscalar charmonium in the decay eta(c)-->K(0)(S)K-/+pi(+/-). We have measured the eta(c) mass to be [2980.4+/-2.3 (stat)+/-0.6 (syst)] MeV and its full width as [27.0+/-5.8 (stat)+/-1.4 (syst)] MeV. We have determined the two-photon partial width of the eta(c) meson to be [7.6+/-0.8 (stat)+/-0.4 (syst)+/-2.3 (br)] keV, with the last uncertainty associated with the decay branching fraction.Study of charmless hadronic B meson decays to pseudoscalar-vector final states.
Phys Rev Lett 85:14 (2000) 2881-2885
Abstract:
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.Measurement of B(Λc +→pK-π+)
Physical Review D - Particles, Fields, Gravitation and Cosmology 62:7 (2000) 1-18
Abstract:
The Λc+→pK-π+ yield has been measured in a sample of two-jet continuum events containing both a charm tag ("D̄") as well as an antiproton (e+e-→D̄p̄X), with the antiproton in the hemisphere opposite the D̄ (measurement of charge conjugate modes is implicit throughout). Under the hypothesis that such selection criteria tag e+e-→D̄p̄Λc+X events, the Λc+→pK-π+ branching fraction can be determined by measuring the pK-π+ yield in the same hemisphere as the antiprotons in our D̄p̄X sample. Three types of D charm tags are used, πsoft- (from D*-→D̄0πsoft-), electrons (from D̄→Xe-v), and fully reconstructed D̄0→K+π- or D- →K+π-π- or Ds-→φπ-. Combining our results obtained from the three independent charm tags, we obtain B(Λc+→pK-π +)=(5.0±0.5±1.2)%. ©2000 The American Physical Society.Measurements of charm fragmentation into Ds *+ and Ds + in e+e- annihilations at √s=10.5 GeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 62:7 (2000) 1-10