We have studied the quasielastic reaction νμn→μ−p in an exposure of the Fermilab deuterium-filled 15-foot bubble chamber to a high-energy wide-band neutrino beam. From an analysis of the Q2 distribution based on the standard V−A theory, the axial-vector mass in a dipole parametrization of the axial-vector form factor is determined to be MA=1.05−0.16+0.12 GeV, consistent with the values previously reported from low-energy experiments.
Measured Quasi-Elastic total cross section.
In an exposure of the deuterium-filled 15 ft bubble chamber, σ(νμn→νμX)σ(νμp→νμX) is measured to be 1.01±0.14. The ratios of neutral-current to charged-current cross sections are 0.30±0.03, 0.22±0.03, and 0.49±0.06 for D2, n, and p targets, respectively, which imply values uL2=0.19±0.06 and dL2=0.13±0.04 for the neutral-current chiral couplings. Evidence for both u- and d-quark jets in neutral-current reactions is observed in distributions of energy fraction of the fastest hadron of either charge from each event.
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Final results for 3678 six-prong π+p events at 8 GeV/c are presented. Single-particle distributions are compared with the predictions of the Chan-Loskiewicz-Allison model and the phenomenological model of the F(t) function. Differences between the transverse momenta of the π+ and π− and between the transverse momenta of secondaries emitted forward and backward in the c.m. system are observed. Cross sections for production of the ρ0, ρ+, ρ−, η, ω0, X0, and D0 mesons and the N33*++ and N33*− isobars are given, together with upper limits for some other resonances. The D0 meson is observed in the seven-body channel in the ηπ+π− system, with some evidence for the cascade decay D0→δ±π∓→ηπ+π−. The branching ratio (f0→2π+2π−)(f0→2π) is determined to be (2.2−2.2+4.5)%. Upper limits for the decay of A mesons into X0π systems are quoted. The cross section for the two-body reaction π+p→N33*++X0 is determined to be 30 ± 13 μb, from which the η0−X0 mixing angle is derived. Associated production of N33*++ and ρ0 in the six-body channel and of N33*++, ρ0, and ω0 in the seven-body channel is studied, and the cross sections for reactions involving simultaneous production of these resonances are estimated. The Goldhaber-Goldhaber-Lee-Pais effect is studied and shown to be strong in the six-body channel, especially for selected events with low energy of the pion system.
TOTAL NUMBER EVENTS=504. DATA FROM T 1.
TOTAL NUMBER EVENTS=1075. DATA FROM T 1.
TOTAL NUMBER EVENTS=425. DATA FROM T 1.
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