Experimental study of hadrons produced in high-energy charged-current neutrino-proton interactions

Abstract

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 $W>\mathrm{}4\mathrm{}$ 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 $Q^2=64\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$, 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.