Search

We have studied the properties of inclusive neutral-strange-particle production in charged-current ..nu..p interactions. The rate for producing at least one neutral strange particle in a charged-current interaction is 0.14 +- 0.02. The inclusive distributions for events with neutral strange particles and for all charged-current events exhibit the same qaulitative behavior. We find no acceptable candidates for the ..delta..S = - ..delta..Q ..lambda.. production reaction ..nu..p ..-->.. ..mu../sup -/2..pi../sup +/..pi../sup -/ in approximately 3000 charged-current events with E/sub ..nu../ > 10 GeV. We find upper limits (relative to the total charged-current sample) for charmed-particle production in any one mass region with subsequent decay into ..lambda..m..pi.. and Km..pi.. final states of 1% and 2%, respectively.

A search for ..mu..e events produced in an antineutrino hydrogen-neon experiment using the Fermilab 15-ft bubble chamber is reported. Based on a single candidate, the 90%-confidence upper limit for the relative yield of ..mu../sup +/e/sup -/ events is 0.5% of all charged-current events with antineutrino energy greater than 10 GeV.

We present results for the reactions vp ..-->.. ..mu../sup -/..pi../sup +/p and vp ..-->.. ..mu../sup -/K/sup +/p at energies above 5 GeV. The average cross section for the first reaction between 15 ad 40 GeV is (0.80 +- 0.12) x 10/sup -38/ cm/sup 2/ and for events with M/sub ..pi../+p-italic < 1.4 GeV is (0.55 +- 0.08) x 10/sup -33/ cm/sup 2/. The ratio of the cross section for the second reaction to that for the first is 0.017 +- 0.010.

We analyze a sample of about 2000 charged-current neutrino-proton interactions with neutrino energy greater than 10 GeV produced in the 15-ft hydrogen bubble chamber at Fermilab using a broad-band neutrino beam. We study the details of the hadrons produced and find generally good agreement with the quark-parton model and present parametrizations of quark fragmentation ($D$) functions. The $D$ functions are found to be independent of ${Q}^{2}$ and $W$ (total hadronic mass) for $Wg4$ GeV, in agreement with the model. The height of the rapidity plateau in the quark (current) fragmentation region is compared to that of the diquark (target) fragmentation region and the two are found to agree. Detailed charge-correlation data are presented and compared to the Field-Feynman model of the $D$ functions, and also to a longitudinal-phase-space model, and are found to disagree with both. The mean transverse momentum ${P}_{T}$ of the hadrons is studied for its ${Q}^{2}$ and Feynman-$X$ dependence. We find a sizeable increase of $〈{{P}_{T}}^{2}〉$ with Feynman $X$ which agrees, however, with our longitudinal-phase-space model. We find no statistically significant dependence of $〈{{P}_{T}}^{2}〉$ on ${Q}^{2}$, up to ${Q}^{2}=64$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$, although the highest-momentum hadrons are consistent with a mild ${Q}^{2}$ dependence. The azimuthal angular distribution of the highest-momentum hadrons in high-${Q}^{2}$ events is examined for evidence of anisotropy of the type that has been predicted for effects of gluon radiation.

The ratio of neutral-current to charged-current cross sections is determined from a sample of events obtained in an exposure of the Fermilab 15-ft hydrogen bubble chamber to a high-energy, horn-focused neutrino beam. For evens with three or more prongs and with visible hadron momentum above 10 GeV/c, the ratio is 0.40 +- 0.14. A Monte Carlo calculation assuming the Weinberg-Salam model is used to correct for excluded events, yielding R/sub NC/CC/ = 0.48 +- 0.17.

We present production and decay distributions for the reaction vp ..-->.. ..mu../sup -/p..pi../sup +/ with M/sub ..pi../+/sub p/ .. ..mu../sup -/..delta../sup + +/, but we find evidence for the presence of non-..delta.. amplitudes for Q/sup 2/ > 1 GeV/sup 2/. The data are fitted by various theoretical models. For Q/sup 2/ < 1 GeV/sup 2/ the best fit yields the value M/sub A/ = 1.25/sup +0.15//sub -0.13/ GeV, using a dipole-nucleon axial-vector form factor in Alder's model, although none of these models successfully reproduces the observed ..delta..-decay distributions.