We use data taken by the Mark II detector at the SLAC storage ring PEP to study inclusive lepton production in e+e- annihilation at 29 GeV. From fits to the inclusive lepton momentum and transverse-momentum spectra we measure the semileptonic branching ratios for charm and bottom hadrons. We also determine with good precision the mean value of the bottom fragmentation function using both electron and muon samples. © 1988 The American Physical Society.

We have made a detailed comparison of the charged-particle flow in three-jet events (e+e-qq»g) and radiative two-jet events (e+e-qq») from e+e- annihilation at Ec.m.=29 GeV. Accurate comparisons can be made because these two event types have similar topologies. In the angular region between the quark and antiquark jets, we observe substantially fewer charged tracks in the two-jet events than in the radiative three-jet events. © 1986 The American Physical Society.

We have searched 205 pb-1 of s =29 GeV data from the Mark II detector at the SLAC e+e- storage ring PEP for events which may signify the existence of a new lepton pair (L-,L0) where the L0 may be massive, but does not exceed the L- mass. Three event signatures for L+L- decay are examined: (i) e, (ii) (e or)(+4), and (iii) (e or )(3+0). The numbers of signature events are found to be in good agreement with Monte Carlo simulations of known background sources. The ranges of L- and L0 masses for which new lepton pairs are excluded are obtained using a likelihood-ratio method to compare the number of observed signature events to the expected background, and to the expected background plus Monte Carlo predictions of (L-,L0) signals. © 1989 The American Physical Society.

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 0.0140.0060.004 -, + per hadronic event. This is roughly 35 times the Lund-model prediction of 0.0004 -, + per hadronic event, but comparable to the Webber-model prediction of 0.006 -, + per hadronic event. The large rate of - production, compared with production rates for other baryons, and with theoretical predictions based on diquark models, indicates that spin suppression does not hold for - production. © 1987 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.

The Production has been investigated by the Mark II collaboration at the SLAC e+e- storage ring PEP. particles are reconstructed by their decay mode. The fragmentation function has been measured and found to be in good agreement with the Lund-model prediction. production has been measured for the first time in high-energy e+e- annihilation. There is evidence at the 3 level for Ds± decay into ± and ±. © 1988 The American Physical Society.

The branching ratios for + and -(n0), n>~1, have been measured to be 0.078 0.005 0.008 and 0.047 ± 0.005 ± 0.008, respectively. The total three-prong tau branching ratio is 0.128 ± 0.005 ± 0.008. Study of the 3± decay indicates that the three pions are predominantly from a JP=1+ state which decays through a 0± intermediate state in a relative s wave. The mass spectrum is suggestive of a resonance. © 1986 The American Physical Society.

We have searched for the lepton-flavor-violating decay D0e in 204 pb-1 of e+e- annihilation data at Ec.m.=29 GeV from the Mark II detector. No candidates were found; we estimate an upper limit on the cross section times branching ratio of (e+e-D0,D0; inclusive)B(D0e)<0.35 pb at the 90% confidence level. Simple assumptions yield the rough limit B(D0e)<2.1×10-3. AE. © 1987 The American Physical Society.

We report a search for long-lived heavy neutrinos produced by the neutral weak current in e+e- annihilation at 29 GeV at the SLAC storage ring PEP. Data from the Mark II detector are examined for evidence of events with one or more separated vertices in the radial range of 2 mm to 10 cm. No events were found that were consistent with the search hypothesis, ruling out heavy neutrinos with mean decay lengths of 1 to 20 cm in the mass range 1 to 13 GeV/c2. © 1987 The American Physical Society.

Inclusive production in e+e- annihilation at 29 GeV has been measured with the Mark II detector. The cross section is found to be 1.10.50.4 pb. After subtraction of the expected contribution from B decay, an upper limit of 0.02 is obtained for other sources of production. © 1988 The American Physical Society.