Experimental estimate of the contribution of secondary absorption processes to production of protons emitted into the backward hemisphere in nucleon-carbon interactions at 4.2 and 10 GeV/c

Experimental data obtained by analyzing stereoscopic photographs of the 2-m propane bubble chamber at the High Energy Laboratory of the Joint Institute for Nuclear Research were used to investigate correlations between protons emitted into the backward hemisphere in the laboratory frame and other accompanying protons produced in nucleon-carbon interactions at 4.2 and 10 GeV/c. The observed kinematic correlations indicate that the production of such photon pairs is in part due to the absorption of low energy positive and neutral pions by quasideuteron pairs in nuclear matter. The contribution of this process is estimated as ∼30% of the inclusive cross section for the emission of photons into the backward hemisphere