Multiplicity distributions in proton–neutron interactions at 400 GeV/c

Abstract

We present a study on the charged multiplicity distribution in proton–neutron (pn) interactions at 400 GeV/c from the data on an exposure of a Fermilab 30-in. deuterium bubble chamber to 400 GeV/c protons. The pn and pp distributions were extracted through an empirical model to correct for double scattering in deuterium. The overall average fraction of the double scattered event is 0.128 ± 0.011. The resulting pn and pp multiplicity distributions give average multiplicities of 8.48 ± 0.10 and 8.99 ± 0.12 respectively. The fraction of pd events which occur off the neutron is 0.52 ± 0.02. The extracted pp distribution parameters are compared with those from the hydrogen bubble chamber (HBC) experiments. Distinctive features of extracted pn distribution are discussed.