The effect of resonance production and diffraction on the inclusive spectra of pions and protons in 19 GeV/c pn interactions

Abstract

Bubble chamber data on pn interactions at 19 GeV/c are used to investigate the effects of nucleon diffraction and resonance production on the inclusivex- andpT2-distributions of protons and pions. We determine the differential distributions of p, π− and π+ due to neutron and proton diffraction and similarly the distributions from the decay of the strong resonances Δ++(1232) and Δ−(1232) and from ρ0(770). Thex-distributions of the protons in the two c.m. hemispheres become quite similar when the effect of diffraction and Δ++ is subtracted. ThepT2-distributions can then be described by a single exponential in the whole kinematic region. The net effect on the shapes of thex-distributions of the pions due to diffraction, Δ++/Δ− and ρ0 production is rather small. The separate effects of these processes on the particle ratio π−/π+ is investigated. By excluding the diffraction and Δ++/Δ− production, the strength of the low-pT2 component of thepT2-distributions of the pions is reduced, but it seems that diffraction and resonance production cannot account for all oft hislow-pT2 enhancement.