Emission of projectile helium fragments in 14N interactions at 2.1 GeV/nucleon: A test of factorization and limiting fragmentation

Abstract

An analysis of projectile helium fragments has been performed from the point of view of testing the factorization and limiting fragmentation hypothesis. An event-by-event examination of 923 interactions of 14N in emulsion at 2.1 GeV per nucleon has been made for target identification. Events with projectile fragments have been divided into various reaction channels according to the multiplicity of He nuclei. The multiplicity distribution, angular structure and other properties of the projectile He fragments have been investigated to see the dependence on different targets and target excitation. The properties of He fragments emitted from the projectile have been found to remain independent of target in peripheral collision processes. The target and projectile breakup properties have been analysed in terms of the collision geometry. Gaussian distributions have been fitted to the projected angular distribution data for He fragments at various intervals of impact parameter and in different reaction channels. The properties of emitted He nuclei exhibit characteristic features of factorization and limiting fragmentation.