We have studied inclusiveΔ++ (1232),∑+ (1385), and∑− (1385) baryon resonance production inK−p interactions at 32 GeV/c. The inclusive and topological cross sections are estimated and compared with published results at lower energies. No energy variation of the cross section is observed forΔ++ (1232) and only a slight decrease is seen in case of∑± (1385). The production properties are investigated through longitudinal and transverse momentum distributions. TheΔ++ (1232) is dominantly produced in the target fragmentation region. The∑+ (1385) is produced both in the target fragmentation region and in the central region, while the∑− (1385) is predominantly produced in the central region. About 20% of the final state protons are produced via aΔ++ (1232) decay and about 25% of the Λ produced come from the decay of∑+ (1385) and∑− (1385).
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On a selected sample of 2171 events, observed in the big heavy liquid bubble chamber Gargamelle at CERN, the charged current total cross section for antineutrino on nucleons has been determined up to the laboratory energy E v ̄ = 8 GeV . The total cross section is found to be a linear function of the antineutrino energy expressed by σ tot (E v ̄ ) = (0.26 ± 0.020) × 10 −38 × E v ̄ ( GeV ) cm 2 . The energy dependence of 〈q 2 〉 v ̄ is found to be given by 〈q 2 〉 v ̄ = (0.15 ± 0.04)E v ̄ + (0.05 ± 0.12) ( GeV /c) 2 . With a simplified nuclear model the ratio of cross sections on neutrons andprotons has been estimated as a function of energy and for two different values of the scaling variable x . The results are compared with the prediction of the naive quark parton model.
Measured charged current total cross section.
The inclusive and semi-inclusive cross sections for K*±(890) and Σ±(1385) resonances are determined in p¯p interactions at 14.75 GeV/c. They account for a large fraction of the KS0 and Λ0 produced. The K*-resonance production also affects the low-pT2 distribution of inclusive KS0. The x distributions of the resonance production are studied in terms of a simple quark-recombination model.
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We have studied inclusive KS0, Λ, and Λ¯ production and strange-resonance production in the reactions pp→(KS0, Λ, or Λ¯)+π±+anything at 405 GeV/c. The observed cross sections are 7.43 ± 0.45 mb for KS0, 4.01 ± 0.35 mb for Λ, and 0.63 ± 0.12 mb for Λ¯. From the analyses of the effective-mass distributions for the (KS0π±), (Λπ±), and (Λ¯π±) systems, the resonance production cross sections are determined as 4.1 ± 1.0 mb for K*+(890), 3.6 ± 1.0 mb for K*−(890), 3.4 ± 1.7 mb for K*±(1420), 0.67 ± 0.12 mb for Σ+(1385), 0.45 ± 0.09 mb for Σ−(1385), and 0.25 ± 0.08 mb for Σ¯±(1385). The inclusive total and differential cross sections are discussed in comparison with data at lower energies. The direct production cross sections for pseudoscalar, vector, and tensor K mesons are estimated to be 2.3 ± 1.2, 3.4 ± 1.0, and 1.7 ± 0.8 mb, respectively. Direct pseudoscalar-K-meson production accounts for less than one-third of the total inclusive kaon production. Evidence of vector-meson dominance in inclusive meson production at high energy is indicated.
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We present results on charged current inclusive neutrino and antineutrino scattering in the neutrino energy range 30–200 GeV. The results include a) total cross-sections; b)y distributions; c) structure functions; and d) scaling violations observed in the structure functions. The results, as well as their comparison with the results of electron and muon inclusive scattering, are in agreement with the expectations of the quark parton model and QCD.
THE VALUES OF Q2 CORRESPONDING TO THE 6 DATA POINTS ARE 1.126,2.11,3.52,4.92,6.33,7.74.
THE VALUES OF Q2 CORRESPONDING TO THE 7 DATA POINTS ARE 1.27,2.25,4.22,7.04,9.85,12.66,15.48.
THE VALUES OF Q2 CORRESPONDING TO THE 8 DATA POINTS ARE 2.11,3.75,7.04,11.72,16.4,21.1,25.8,30.5.
This paper gives the results of a study of inelastic charged-current interactions of muon-type neutrinos with hydrogen and deuterium targets using the Argonne 12-foot bubble chamber. We discuss in detail the separation of the events from background. For the single-pion production reactions νp→μ−pπ+, νn→μ−nπ+, and νn→μ−pπ0, energy-dependent cross sections, differential cross sections, invariant-mass distributions, and the Δ++(1236) decay angular distribution are presented. These data are also used to study the isospin properties of the πN system. Comparisons of the data with models of single-pion production are made, and a direct test of partial conservation of the axial-vector current is discussed. Cross sections and invariant-mass distributions are given for the reactions in which more than one pion is produced. Ten events of strange-particle production were found, and the properties of these events are discussed. The energy dependence of the total νp and νn cross sections from threshold to 6 GeV was determined, and the σ(νn)σ(νp) ratio measured. This ratio and the inclusive x and y distributions rapidly approach the scaling distributions expected from the quark-parton model.
Measured charged current total cross section.
Inclusive and semi-inclusive cross sections for gp0 production in 100, 200, and 360 GeV/c π−p interactions are presented. Differential cross sections for ρ0 production as functions of c.m. rapidity and transverse momentum are compared with the corresponding differential cross sections for pion production. Effects of various methods of estimating background on the values obtained for ρ0 production cross sections are discussed. About 10% of the final-state charged pions appear to come from ρ0 decay. Thus, while ρ0 production and decay is a significant source of final-state pions, other sources must contribute the majority of the produced pions.
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We present results for the reactions νp→μ−π+p and νp→μ−K+p at energies above 5 GeV. The average cross section for the first reaction between 15 and 40 GeV is (0.80±0.12) × 10−38 cm2 and for events with Mπ+p<1.4 GeV is (0.55±0.08) × 10−38 cm2. The ratio of the cross section for the second reaction to that for the first is 0.017±0.010.
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RAPIDITY IS MEASURED IN 'QUARK' REST FRAME DEFINED AS Y(Q)=Y(LAB)-LOG(W**2/M**2) WHERE Y(LAB)=0.5*LOG((E+PL)/(E-PL)).
We present results for the differential cross sections of neutrinos and antineutrinos on nucleons in the energy range E = 2−200 GeV, from the BEBC and Gargamelle experiments. The structure functions F 2 , 2 χF 1 and χF 3 have been evaluated as a function of χ and q 2 . Deviations are observed from Bjorken scaling, which are very similar to those found in electron and muon inelastic scattering. For the Callan-Gross ratio, we find 2χF 1 F 2 = 0.80 ± 0.12 and the corresponding value for 〈R〉 = 〈 σ S σ T 〉 = 0.15 ± 0.10 . Our results are consistent with the Gross-Llewellyn-Smith sum rule; we measure ⩾2.5 ± 0.5 valence quarks per nucleon. Quark and antiquark distributions are given. The Nachtmann moments of F 2 and χF 3 are quantitatively consistent with the predictions from QCD. The value of the strong interaction parameter is λ = 0.74 ± 0.05 GeV without corrections, and 0.66 ± 0.05 GeV including α S 2 corrections. The moments of the gluon distribution are found to be positive and indicate an χ distribution of gluons which is comparable with that of the valence quarks.
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Inclusive and semi-inclusive distributions of γ's and π 0 's in the reactions K + p → γ + X and K + p → π 0 + X at 32 GeV/ c are presented and discussed. When compared to the inclusive π − production, the π 0 cross section is found to be significantly higher in low | x | and p T regions. The data are compared with other experiments and quark fusion model predictions.
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ESTIMATED FROM GAMMA AND 2GAMMA SPECTRA.
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