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.

A search for single electrons from the decay of singly produced scalar electrons has been made at the PEP storage ring at SLAC. No events of this type have been found in 123 pb-1 of data, resulting in a cross-section limit of less than 2.4×10-2 pb within the detector acceptance, and a 95%-confidence-level lower limit on the scalar-electron mass of 22.2 GeV/c2. © 1983 The American Physical Society.

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.

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.

A peak in the pK-+ and p»K+- invariant-mass spectra at 2.2850.006 GeV/c2 is observed, which is associated with the lowest-lying charmed baryon (c). A cross section times branching ratio of 0.0370.012 nb at Ec.m.=5.2 GeV is measured with a substantial fraction of the events produced with an equal recoiling mass. New measurements of inclusive p and cross sections are also presented, allowing an estimate of the branching ratio B(c+pK-+)=0.0220.010. © 1980 The American Physical Society.

A high-statistics study of decays into baryon final states has been done with the Mark II detector at SPEAR. A detailed test of baryon-antibaryon decay modes is presented. Substantial resonance formation is observed in multibody decays of the involving baryons. Branching ratios for a large number of decay modes are given, including the radiative decay pp. The flavor-SU(3)-forbidden decays (1385)+charge conjugate are observed with substantial branching ratios. © 1984 The American Physical Society.

We present a measurement of the cross section for the reaction e+e-→ e+e-π+π-π+π-at SPEAR. This channel is found to be large and dominated by the process γγ → ρ{variant}0ρ{variant}0→ π+π-π+π-. The cross section, which is small just above the four-pion threshold, exhibits a large enhancement near the ρ{variant}0ρ{variant}0threshold. © 1981.

We have used a high-resolution drift chamber in the Mark II detector at the SLAC e+e- storage ring PEP to measure the lifetimes of the D0 and D+ mesons produced in e+e- annihilations at 29 GeV. Based on a sample of 74 decays for the D0 mesons and 23 decays for the D+ mesons, the lifetimes are found to be &=(4.7-0.8+0.9) 0.5×10-13 sec and &=(8.9-2.7+3.8) 1.3×10-13 sec. This leads to a ratio of lifetimes &=1.9-0.7 0.3+0.9.. AE © 1986 The American Physical Society.