We have measured the electron, muon, and charged-hadron pair production rates in two-phonon interactions for invariant masses above 2.0 GeV over a large of momentum transfer. The cross sections for electron and muon pairs show good agreement with the QED predictions at both small and large momentum transfer. The observed rate of hadron production is less than 6% of the rate that QED predicts for point-like hadrons, consistent with recent leading-order QCD calculations.
LOW Q**2 CROSS SECTIONS.
DIFFERENTIAL CROSS SECTIONS IN THE INVARIANT MASS FOR MUON AND ELECTRON PAIRS IN THE UNTAGGED, LOW Q**2 REGION.
HIGH Q**2 CROSS SECTIONS.
Charged-current neutrino interactions have been analysed in a sample of pictures from BEBC equipped with a TST. Using a method independent of both the neutrino flux and nuclear interaction corrections, the ratio R = σ n / σ p has been measured. The result is R =1.98±0.19 for the ratio of total cross sections. Bjorken x distributions for proton and neutron targets and for u and d quarks are compared.
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In this Letter, a measurement of inclusive muon production (pμ>2 GeV/c) in e+e− annihilation into hadrons at center-of-mass energies from s=12 to 31.6 GeV is reported. The results agree with the expected semileptonic decays from charmed and bottom mesons.
MUONS PER HADRONIC EVENT.
INVARIANT CROSS SECTION, ASSUMING HADRONIC CROSS SECTION HAS R VALUE OF 3.9 +- 0.5.
Charged- and neutral-particle production from 400-GeV/c pp collisions are measured simultaneously using the Fermilab 15-ft bubble chamber. The π0 and K0 cross sections are rising at Fermilab energies, while the Λ0 cross section remains fairly constant. Similarly, the average number of π0's and K0's increases as a function of the number of negative particles in an event, yet no such dependence is noted for the Λ0's. The ratio of average number of π0 to average number of π− per inelastic collisions is found to be constant at Serpukhov and Fermilab energies (40 to 400 GeV/c) and equal to 1.22±0.02. Cross sections for Σ0 and Σ¯0 production are measured and limits are found for η0 and ω0 production. Neutral- and charged-pion correlations are compared with five pion-production models.
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We have measured deep inelastic muon-deuteron scattering in the range 0.4<Q2<3.4 and 1.6<ν<5.6 GeV. We have extracted the neutron structure function and find that νW2n differs significantly from νW2p, as also found in e−d scattering. To compare μ−d and e−d scattering we form the ratio r(Q2)=(νW2)μd(νW2)ed=N(1+Q2Λ2)−2 and find N=0.925±0.038 and 1Λ2=−0.019±0.016.
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We have measured muon-proton deep inelastic scattering in the range 0.4<q2<3.6 (GeV/c)2. The data are consistent with muon-electron universality, and if the ratio ρ=νW2(μ−p)νW2(e−p) is fitted with the form ρ=N(1+q2Λ2)−2, we obtain N=0.997±0.043 and Λ−2=+0.006±0.016 (GeV/c)2. This result establishes that |Λ|>~5.1 GeV/c with 95% confidence.
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