Two source emission behaviour of alpha fragments of projectile having energy around 1 GeV per nucleon

TL;DR

This study investigates the two-source emission behavior of alpha fragments from relativistic ^{84}Kr interactions, revealing that most originate from a cold source with a minor hot source contribution, and the source temperatures depend on projectile mass.

Contribution

It introduces a two-source emission model for alpha fragments in relativistic heavy-ion collisions, challenging the traditional Participant-Spectator model assumptions.

Findings

Alpha fragments mainly emitted from a cold source.

Hot source contribution is only a few percent.

Source temperatures vary with projectile mass number.

Abstract

The emission of projectile fragments alpha has been studied in ^{84}Kr interactions with nuclei of the nuclear emulsion detector composition at relativistic energy below 2 GeV per nucleon. The angular distribution of projectile fragments alpha in terms of transverse momentum could not be explained by a straight and clean-cut collision geometry hypothesis of Participant - Spectator (PS) Model. Therefore, it is assumed that projectile fragments alpha were produced from two separate sources that belong to the projectile spectator region differing drastically in their temperatures. It has been clearly observed that the emission of projectile fragments alpha are from two different sources. The contribution of projectile fragments alpha from contact layer or hot source is a few percent of the total emission of projectile fragments alphas. Most of the projectile fragments alphas are emitted from the cold source. It has been noticed that the temperature of hot and cold regions are dependent on the projectile mass number.