Dimuon production is studied in 400-GeV proton-nucleus collisions. A strong enhancement is observed at 9.5 GeV mass in a sample of 9000 dimuon events with a mass $m_{\mu^+\mu^-} \to$ 5 GeV.
Two peaks were observed. Mass spectrum was fitted to one and two resonance hypothesis.
We report measurements of semi-inclusive pion electroproduction from both hydrogen and deuterium targets carried out at the Wilson Synchrotron Laboratory at Cornell University. Measurements were made at the (W, Q2) points (2.15 GeV, 1.2 GeV2), (2.15, 4.0), and (3.11, 1.2) with hydrogen and deuterium, and at (2.15, 2.0), (2.67, 3.3), and (3.11, 1.7) with hydrogen only. The invariant virtual-photoproduction cross section for pions scaled by the total cross section is studied as a function of x′, pT2, W, and Q2. The invariant structure function shows no Q2 dependence and a weak W dependence. The ratio of π+ to π− production is also presented, but a distinction between a universal ω or W dependence cannot be made.
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We have measured the invariant cross section for inclusive ϕ production in proton-nucleus collisions at 400 GeV/c near Feynman x=0. For transverse momenta in the range between 0.8 and 3.5 GeV/c the ratio of ϕ to π− rises from 1 to 7%. We also report on correlations with particles opposite the ϕ in the center-of-mass system as they relate to the Okubo-Zweig-Iizuka rule.
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This paper reports measurements of the inclusive pion electroproduction reaction e+N→e+π±+ anything with both proton and neutron targets for pions produced along and near the direction of the virtual photon. Two independent purposes of these measurements were to provide data at low ε and at high Q2. Data are reported for the (W,Q2,ε) points (2.2 GeV, 1.2 GeV2, 0.45), (2.7, 2.0, 0.35), (2.7, 3.3, 0.40), (2.7, 6.2, 0.40), and (2.7, 9.5, 0.40). The data are used to test Feynman scaling and to compare the ratio of the cross sections for charged-pion production to the quark-model predictions. The data are also used in conjunction with the data from earlier experiments to separate the scalar and transverse components of the cross section.
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The multiplicity distribution of inclusive electron events above 4 GeV cm energy shows two distinct classes of events: two prong no photon and high multiplicity events. If the high multiplicity events are attributed to the semi-leptonic decay of charmed particles the two prong no photon events must come from the weak decay of a different type of particle. The charged K to π ratio was measured for these events. The average number of charged kaons is 0.07 ± 0.06 per two prong event and 0.90 ± 0.18 per multiprong event. Thus the weak current responsible for the low multiplicity events has a small coupling to strange particles.
NUMBER OF CHARGED PARTICLES OBSERVED .EQ. 2.
NUMBER OF CHARGED PARTICLES OBSERVED .GE. 3.
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.
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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.
Results are presented on the inclusive reactions p p → K 0 X , p p → Λ X and p p → Λ X at an incident antiproton momentum of 12 GeV/ c in BEBC. The cross sections are studied as functions of the Feynman scaling variable x , the rapidity, the transverse momentum of the V 0 and the missing mass squared. The dependence of the Λ and Λ polarization on x are also studied. Comparisons with proton-proton data at 12 GeV/ c are also made. Finally, events with two detected V 0 are analyzed in order to study correlations arising from the production of two strange neutral particles.
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We have measured the inclusive production of massive dimuons (7<~Mμμ<~11 GeV/c2) by 200-, 300-, and 400-GeV protons incident on Cu in order to check whether the dimensionless cross section Mμμ3[dσdMμμdy]y=0 is a function of Mμμ2s alone, where s is the square of the c.m. energy. The results support the scaling hypothesis.
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Charged hadron production via e + e − → h ± X where h ± = π ± , K ± , p ̄ has been measured for s values between 13 and 25 GeV 2 . Inclusive cross sections and the evidence for scaling are presented.
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The total cross section for K ± production in e + e − collisions was measured for cms energies between 3.6 and 5 GeV and was found to increase by a factor of 2–3 from 3.6 to 4.1 GeV.
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