Using the CLEO detector at the Cornell Electron Storage Ring, we have measured the muonic branching fractions B of the (1S) and (3S) to be (2.520.070.07)% and (2.020.190.33)%, respectively. © 1989 The American Physical Society.

We report a measurement of the lifetime of the B0 meson based upon 29-GeV e+e- annihilation data taken with the Mark II detector at the SLAC storage ring PEP. The B0 mesons are tagged by their decays into D*- and D*+, where the D*- is tagged by its decay into -D 0. We reconstruct the decay vertices of 15 B0-meson candidates and measure the B0 lifetime to be 1.20-0.360.14+0.52+0.16 psec. © 1990 The American Physical Society.

We have searched for the annihilation of e+e- into the exclusive channels e and at s =29 GeV, using 226 and 133 pb-1, respectively, of data taken with the Mark II detector at the SLAC storage ring PEP. The resulting candidate sample is compatible with the expected background from pair production. Our analysis yields 95%-C.L. cross-section limits of e/<1.8×10-3 and /<6.1×10-3, where is the QED cross section for production of a lepton pair. This is the first high-Q2 test of lepton-flavor conservation involving leptons. © 1991 The American Physical Society.

Using the CLEO detector at the Cornell Electron Storage Ring, we have found evidence for L=1 charmed mesons in e+e- annihilations. We observe a D**0 state at mass 2461±3±1 MeV/c2 and width 20-12-10+9+9 MeV/c2 decaying to D+-. We also see an enhancement in the m(D*+-)-m(D*+) mass-difference spectrum and by examining D*+ decay-angle dependence, we see structure consistent with two states decaying to D*+-. We observe a lower-mass state, at mass (2428±3±2) MeV/c2 and width (23-6-4+8+10) MeV/c2, assuming that the higher-mass component is from the decay D**0(2461)D*+-. We present arguments for the spin-parity assignments of these states. We also report observation of candidate L=1 cs» state decaying to D*+Ks0. © 1990 The American Physical Society.

Data taken by the Mark II detector at the SLAC e+e- storage ring PEP was used to search for exclusive decays of D and B mesons into two charged leptons plus a charged pion or kaon. All possible charge and lepton combinations consistent with charge conservation were considered and no evidence for any signals was found. We obtain upper limits for the various branching ratios ranging from 2.5×10-3 to 9.2×10-3, at a 90% confidence level. Some of these limits can be used to constrain leptoquark masses in various models. © 1990 The American Physical Society.

We have studied the energy-energy correlation in e+e- annihilation into hadrons at s =29 GeV using the Mark II detector at the SLAC storage ring PEP. We find to O(s2) that s=0.1580.0030.008 if hadronization is described by string fragmentation. Independent fragmentation schemes give s=0.100.14, and give poor agreement with the data. A leading-log shower fragmentation model is found to describe the data well. © 1988 The American Physical Society.

We have searched for neutrinoless decays into three charged particles. Evidence of such decays would demonstrate nonconservation of lepton flavor and, in some cases, lepton number. We see no signal for any such neutrinoless decays and set upper limits on their branching fractions. © 1990 The American Physical Society.

A precise measurement of the ratio R of the total cross section e+e-hadrons to the pointlike cross section e+e-+- at a center-of-mass energy of 29.0 GeV is presented. The data were taken with the upgraded Mark II detector at the SLAC storage ring PEP. The result is R=3.920.050.09. The luminosity has been determined with three independent luminosity monitors measuring Bhabha scattering at different angular intervals. Recent calculations of higher-order QED radiative corrections are used to estimate the systematic error due to missing higher-order radiative corrections in the Monte Carlo event generators. © 1991 The American Physical Society.

Using an impact-parameter tag to select an enriched sample of Z0bb» events, we have measured the difference between the average charged multiplicity of bb» and all hadronic Z0 decays to be 2.11.8(stat) 0.6(syst) tracks per event. The resulting total (nonleading) charged multiplicity for Z0 bb» events is 23.1(12.0)1.8 0.6 tracks. A comparison of this nonleading multiplicity to hadronic multiplicity data in the range of 10 to 60 GeV supports the hypothesis of flavor-independent hadronic fragmentation, and yields a measurement of the average energy fraction of bottom hadrons in Z0 decays of xEb=0.620.100.04. © 1992 The American Physical Society.

We have measured the mass of the Z boson to be 91.110.23 GeV/c2, and its width to be 1.61-0.43+0.60 GeV. If we constrain the visible width to its standard-model value, we find the partial width to invisible decay modes to be 0.620.23 GeV, corresponding to 3.81.4 neutrino species. © 1989 The American Physical Society.