P. Schreiner

Neutrino production of the Δ(1236)

New data for the reaction νp → μ−π+p near 1 GeV/c neutrino momentum are consistent with complete dominance by the quasi-two-body reaction νp → μ− Δ++(1236). It is shown how information about the N-Δ axial current transition matrix element can be extracted from this data. Various predictions for the matrix elements are reviewed and tested against the experimental results. The data are consistent with the PCAC prediction for dσ/dq2 near q2 = O. In contrast to previous findings, Adlers relativistic version of the static model is reasonably successful in fitting the data. Zuckers model also fits the data. Finally, the implications of these results for future experiments are discussed.

Two-particle rapidity correlations in 205 GeV/c pp interactions

Abstract Using data obtained from an exposure of the 30-inch bubble chamber at NAL, inclusive and semi-inclusive two-particle rapidity correlations are analyzed for charged-charged, −−, ++, and ± particles. For the inclusive sample, positive correlations are observed in the central region. In the semi-inclusive case, the four-and six-prong events exhibit strong positive correlations near 90° CM. Selection of four-prong events with a large rapidity gap shows that the strong correlation seems to be associated with diffractive-type events.

Inclusive ηp and ηn charged-current neutrino reactions below 6 GeV☆

Abstract Results are presented of a study of inclusive ηp and ηn interactions from threshold to 6 GeV. The data show a rapid approach to the distributions expected in the naive quark-parton model. The charged-current η deuteron total cross section is fit by the expression σ T ( η d) = (0.76 ± 0.03) × 10 −38 E η cm 2 per GeV per nucleon. For E η > 1.5 GeV, we measure σ T ( η n)/ σ T ( η p) = (2.02 ± 0.23). The distributions in the scaling variables x and y are given and discussed.

Comparison of jet size in νp interactions with that in e+e− annihilation

Abstract Using new ν p charged-current data from the Fermilab 15 foot hydrogen bubble chamber, some properties of the ν -induced hadronic jets are studied. The angular size of the jets is measured and compared with results from e + e − annihilation. The jets in the two processes are found to be quite similar in terms of the variables sphericity, thrust, and energy flow.

Study of the reaction νn→νpπ−

Abstract We have measured the excitation function for the neutral current process νn→νpπ− as a function of neutrino energy. Our data give a cross section ratio R=σ(νpπ−)/σ(μ−pπ+)=0.11±0.022 over the energy interval (0.3⩽E ν⩽1.5)GeV. This measurement of single-pion production in a kinematically defined reaction is the first to use a deuterium target. The R value, as well as other characteristics of the data, agrees with the Adler model for single-pion production via the neutral current and gives a value of sin2θw=0.26±0.09.

Inclusive ϱ0 production in νp charged-current interactions

Abstract Using data from the Fermilab 15 ft hydrogen bubble chamber, we have studied inclusive ϱ0 production in antineutrino-proton charged-current interactions. We measure (0.21 ± 0.03) ϱ0/event, corresponding to ϱ0/π−=0.12 ± 0.02. As a function of Q2 and for hadronic masses above a threshold region, the ϱ0/π− ratio shows little variation. At least 50% of the ϱ0s are consistent with coming from the current fragmentation region. The results agree reasonably well with the predictions of the quark fragmentation model of Feynman and field.

A test of quark fragmentation in the quark-parton model framework

Abstract The hadronic system produced in charged-current antineutrino interactions is used to study fragmentation of the d-quark. Some problems encountered in defining the current quark fragments are discussed. The properties of the fragmentation function are in good agreement with the expectations of the naive quark-parton model and, in particular, at the present level of statistics we find no need for either a Q 2 -or an x BJ -dependence.

Study of the reaction νp → μ+pπ−

Abstract We present data on the reaction ν p → μ + pπ − from an exposure of the Fermilab 15 ft hydrogen bubble chamber. The channel cross section for 5 GeV ν GeV and M( p π − ) GeV is σ = (27 ± 5) × 10 −40 cm 2 . This cross section is dominated by the I = 1 2 production amplitude.

Study of the Reaction Neutrino

Abstract We have measured the excitation function for the neutral current process νn→νpπ− as a function of neutrino energy. Our data give a cross section ratio R=σ(νpπ−)/σ(μ−pπ+)=0.11±0.022 over the energy interval (0.3⩽E ν⩽1.5)GeV. This measurement of single-pion production in a kinematically defined reaction is the first to use a deuterium target. The R value, as well as other characteristics of the data, agrees with the Adler model for single-pion production via the neutral current and gives a value of sin2θw=0.26±0.09.

N \to

Abstract We present data on the reaction ν p → μ + pπ − from an exposure of the Fermilab 15 ft hydrogen bubble chamber. The channel cross section for 5 GeV ν GeV and M( p π − ) GeV is σ = (27 ± 5) × 10 −40 cm 2 . This cross section is dominated by the I = 1 2 production amplitude.