The τ lifetime was measured with the Mark II vertex detector at the storage ring PEP. ττ=(3.20±0.41±0.35)×10-13 sec was found, which agrees well with e-μ-τ university. © 1983 The American Physical Society.

We have studied several features of the production of charged-hardon pairs by γγ collisions. We have measured the f0 partial width Γf0→γγ(Q2) for Q2 in the range 0

The total momentum and transverse momentum spectra of electrons in e+e- annihilation at 29 GeV have been measured. The inclusive cross section is determined to be 14.4±1.6±5.2 pb for momenta greater than 2 GeV/c. The average semielectronic branching ratios of charm and bottom quarks are measured to be (6.3±1.2±2.1)% and (11.6±2.1±1.7)%, respectively. The fragmentation function for bottom quarks is determined to be peaked at high z, with zb=0.75±0.05±0.04. © 1983 The American Physical Society.

A search has been made for the inclusive production of J ψ (3.1) and Υ{hooked} (9.4) mesons in e+e- interactions at 29 GeV, via their decay into two leptons. No signal is observed in the J ψ region, nor in the Υ{hooked} region. The limits on the cross sections are σ(e+e- → ψX) < 4.4 × 10-36cm2, and σ(e+e- → Υ{hooked}X) < 4.7 × 10-36 cm2. The same data yield limits on the branching ratios for the b quark BR (b → ψX) < 4.9% and BR (b → ℓ+ℓ-X) < 0.8%. © 1983.

A measurement of jet energy spread in the reaction e+e- → hadrons is presented. Using a jet calculus model for the jet development we determine the variation of the strong coupling constant with respect to momentum transfer. The observed variation is consistent with that expected for QCD over a wide range of momentum transfers. This method alone is not sufficient to distinguish QCD from simple limited transverse momentum models. © 1983.

Inclusive - production in e+e- annihilation at 29 GeV has been measured with the Mark II detector. From an integrated luminosity of 207 pb-1, we determine a production rate of 0.0170.0040.004 -++ per hadronic event. A search for *0(1530)-+ leads to an upper limit of N(*0)/N(-)<0.35 at a 90% confidence level. © 1987 The American Physical Society.

We have measured the branching fraction of -'-1/2 to be (22.3±0.6±1.4)% and the branching fraction of -'K*-1/2 to be (1.3±0.3±0.3)%. These values are consistent with the expectations for conventional decays of the . © 1986 The American Physical Society.

The branching fraction for -5(0) is measured from data accumulated with the Mark II detector at PEP. Four events are observed with an estimated hadronic background of (0.03-0.02+0.04) events and a background from -30 of (0.05-0.04+0.07) events. This results in a measured branching fraction of (0.160.080.04)%. The candidate events are used to establish an upper limit of 125 MeV/c2 on the mass at the 95% confidence level. © 1985 The American Physical Society.

We have used a high-resolution drift chamber in the Mark II detector at the SLAC storage ring PEP to measure the lifetime of leptons produced in e+e- annihilations at 29 GeV. Based on the flight-path distribution of 807 three-prong decays, the lifetime is found to be (2.880.16 0.17)×10-13 sec, in agreement with expectations for e - universality. © 1988 The American Physical Society.

The average lifetime of bottom hadrons was measured with the Mark II vertex detector at the storage ring PEP. The lifetime was determined by measuring the impact parameters of leptons produced in bottom decays. τb=(12.0-3.6+4. 5±3.0)×10-13 sec was found. © 1983 The American Physical Society.