Possible mechanisms for production of slow target fragments

Abstract

In this paper, we investigate the possible mechanisms, which are responsible for the production of slow target fragments with energy [Formula: see text][Formula: see text]MeV that are emitted from interactions of [Formula: see text]Si nucleus with emulsion nuclei at energy 14.6[Formula: see text]GeV per nucleon. Angular distributions of slow fragments are compared with the corresponding results from collisions of 1H, 3He, 4He, 7Li and [Formula: see text]C with emulsion at the energy range 2.2–3.7[Formula: see text]A[Formula: see text]GeV. We investigate the effects of both projectile energy and mass number on the angular distributions for slow secondary charged fragments called gray and black track producing particles. The average emission angles are found to be [Formula: see text] and [Formula: see text] for gray and black tracks, respectively. These values are nearly constant for all compared experiments. There are two different mechanisms of gray particle production in forward and backward directions while there is a single symmetric mechanism for black particles in both directions. The temperatures are found to be 58 and 6[Formula: see text]MeV for systems of emissions for gray and black particles, respectively. There are strong effects of target size on those mechanisms. The emission system of these particles becomes slower and shows low temperature with the increase in volume of target nucleus.