The production of Λ hyperons in e+e− annihilation has been measured as a function of their total momenta, transverse momenta, and the event thrust. The total production rate is 0.213±0.012±0.018 Λ or Λ¯ per hadronic event. The observation of correlations in rapidity and angles for events with two detected Λ decays supports fragmentation models with local baryon-number compensation.
No description provided.
No description provided.
No description provided.
We have measured the K0+K¯ 0 inclusive cross section in e+e− annihilation at 29 GeV with the Mark II detector SLAC PEP. We find 1.27±0.03±0.15 K0+K¯ 0 per hadronic event. We have also used time-of-flight particle identification to measure the K± rate over the momentum range 300–900 MeV/c.
Extrapolated to full momentum range by Monte-Carlo.
Statistical errors only.
No description provided.
We report a measurement of the inclusive charged-particle distribution for gluon jets derived from nearly threefold-symmetric three-jet events taken at center-of-mass energy of 29 GeV in e+e− annihilation. The charged-particle spectrum for these jets is observed to fall off more rapidly than those of quark jets of the same energy.
Errors include both statistics and the uncertainty in correction factors. X is defined at the energy of the individual particle divided by the total energy of the jet to which it is assigned.
Inclusive Ω− 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 0.014±0.006±0.004 Ω−, Ω¯+ per hadronic event. This is roughly 35 times the Lund-model prediction of 0.0004 Ω−, Ω¯+ per hadronic event, but comparable to the Webber-model prediction of 0.006 Ω−, Ω¯+ per hadronic event. The large rate of Ω− production, compared with production rates for other baryons, and with theoretical predictions based on diquark models, indicates that spin suppression does not hold for Ω− production.
Radiatively corrected inclusive cross section.
Extrapolation to full momentum range.
Inclusive Ξ− 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 0.017±0.004±0.004 Ξ−+Ξ¯+ per hadronic event. A search for Ξ*0(1530)→Ξ−π+ leads to an upper limit of N(Ξ*0)/N(Ξ−)<0.35 at a 90% confidence level.
Numerical values supplied by S. Klein.
Extrapolation over full x range using LUND Monte Carlo.
The production of enutral kaons in e + e − annihilation has been measured for c.m. energies between 3.4 GeV and 7.6 GeV. Near 4 GeV the inclusive K S cross section shows an increase and structure similar to total hadron production. Roughly 40–45% of all hadronic final states contain kaons, except at 4.028 GeV and 4.415 GeV, where a significantly larger kaon fraction is observed.
No description provided.
THIS IS TWICE THE MEASURED KS CROSS SECTION. THE ERRORS ARE STATISTICAL ONLY. THERE IS 15 PCT ABSOLUTE NORMALIZATION ERROR, PLUS POSSIBLY SOME ENERGY DEPENDENT ERROR. THE DATA ARE NOT EQUALLY SPACED IN THE ENERGY INTERVALS.
Measurements of multihadron production in e+e− annihilation at center-of-mass energies between 2.6 and 7.8 GeV are presented. Aside from the narrow resonances ψ(3095) and ψ(3684), the total hadronic cross section is found to be approximately 2.7 times the cross section for the production of muon pairs at c.m. energies below 3.7 GeV and 4.3 times the muon-pair cross section at c.m. energies above 5.5 GeV. Complicated structure is found at intermediate energies. Charged-particle multiplicities and inclusive momentum distributions are presented.
ERRORS ARE STATISTICAL ONLY.
ERRORS INCLUDE SYSTEMATICS.
R WITH SMALLER BINNING AROUND RESONANCE REGION. ERRORS ARE STATISTICAL ONLY.
Measurements are presented of the inclusive charged-particle cross sections s dσdx for e+e− annihilation at center-of-mass energies of 5.2, 6.5, and 29.0 GeV. Significant scale breaking is observed in these cross sections.
CROSS SECTION S*D(SIG)/DX FOR CHARGED PARTICLES AT SQRT(S) = 5.2, 6.5 AND 29.0 GEV. NUMERICAL VALUES OF DATA TAKEN FROM THESIS OF J.F. PATRICK LBL-14585.
Inclusive momentum and energy spectra of neutral and charged D-mesons produced in e + e − annihilation at energies near 7 GeV are presented. The slope of the energy spectrum is similar to the charged pion spectrum at the same energy. The inclusive cross section σ(e + e − → D or D + anything) at 7 GeV is 4.8±1.3 nb.
No description provided.
No description provided.
SCALING VARIABLE IS X(P=3,DEF=2*E(P=3)/SQRT(S)) > 0.54.
We have measured inclusive distributions for charged particles in hadronic decays of the Z boson. The variables chosen for study were charged-particle multiplicity, scaled momentum, and momenta transverse to the sphericity axes. The distributions have been corrected for detector effects and are compared with data from e+e− annihilation at lower energies and with the predictions of several QCD-based models. The data are in reasonable agreement with expectations.
Mean corrected charged particle multiplicity.
Corrected charged particle X distributions. Errors are statistical and systematic combined.
Corrected charged particle PTIN distributions. Errors are statistical and systematic combined.