Study of backward-produced protons in π−-nucleus interactions at 40 GeV/c

Abstract

The backward production of protons in the reaction π−A → p↓X is studied at 40 GeV incident energy with the different nuclear targets : C, Cu, Pb. The structure function shows a slope independent of the target atomic weightA and slightly dependent on the proton production angle. The invariant cross-section, normalized to the nucleon, increases withA up to a plateau which varies with the incident energy. Finally the ratiosR = (FA/A)/(FC/AC) andn = ln(FA/FC)/ln(A/AC), whereF = (E/p2)(d2σ/(dp dΩ)), show a flat dependence on the momentum of the proton backward produced. These results are in favour of few-nucleon correlation models.