Properties of the Hadronic System Resulting from anti-Muon-neutrino p Interactions

The properties of the final-state hadronic system in antineutrino-proton charged-current interactions are presented. The events were observed in Fermilab 15-foot hydrogen bubble chamber. The average energy of the events is - 30 GeV, but there are some interactions beyond 100 GeV. The mean multiplicity of the charged hadrons varies as = (0.06 +- 0.60) + (1.22 +- 0.03)lnW/sup 2/ for hadronic masses W in the range 1.0 < W/sup 2/ < 50 GeV/sup 2/. By contrast, the multiplicity depends only weakly on the four-momentum transfer between the leptons. The mean pion multiplicities for events with three or more charged tracks are found to be = 1.64 +- 0.04, = 1.16 +- 0.13, for ..pi../sup -/ and ..pi../sup 0/ production, respectively. By comparing the number of positive tracks with ..pi../sup -/ data from neutrino production, we deduce a mean proton multiplicity of 0.53 +- 0.15. The single-particle distributions in both longitudinal and transverse momentum are found to be similar to those for nondiffractive production in hadronic collisions. The fragmentation properties of the final-state d quarks are compared to the expectations of the quark-parton model. The fraction of observed neutral-strange-particle production for events with three or more charged tracks is 0.08 +-more » 0.015 and is consistent with coming completely from associated production.« less