Shower and Slow Particle Productions in Nucleus-Nucleus Collisions at High Energy

S Fakhraddin,Magda A Rahim,Hamdy M M Zayd

doi:10.1155/2014/403504

S Fakhraddin, Magda A Rahim + Show 1 more

Open Access

https://doi.org/10.1155/2014/403504

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Abstract

The multiplicity distributions of shower, grey, and black particles produced in interactions of4He,12C,16O,22Ne, and28Si with emulsion (Em) at 4.1–4.5 A GeV/c beam energies, and their dependence on target groups (H, CNO, and AgBr) is presented and has been reproduced by multisource thermal model. The multiplicity and the angular distributions of the three types of particles have been investigated. The experimental results are compared with the corresponding ones from the model. We found that the experimental data agrees with theoretical calculations using multisource thermal model.

Highlights

Study of the secondary charged particles produced in heavy ion collisions is attracting a great deal of attention during the recent ten years
The measurements show that the average multiplicity of shower, grey particles increases with increase in projectile mass, but the average multiplicity of black particles is approximately constant
The weight kj in (5) is obtained by the geometrical weight of the impact parameter. This formula was first proposed by Liu et al to describe the multiplicity distributions of final-state particles produced in “elementary” particle interactions and heavy ion collisions at high energies

Summary

Introduction

Study of the secondary charged particles produced in heavy ion collisions is attracting a great deal of attention during the recent ten years. Since the first run of the Dubna Synchrophasotron, in 1980, a lot of data for nuclear fragmentation in light- and heavy-ion collisions at high energy have been collected [1–5]. The measurements show that the average multiplicity of shower, grey particles increases with increase in projectile mass, but the average multiplicity of black particles is approximately constant. These observations have generated a flurry of theoretical activities [6–11]. Others concern the thermal characteristics of final-state particles and fragments. One of these thermal models is the multisource thermal model, proposed to explain the multiplicity and angular distributions, based on the assumption that many emission sources are assumed to be formed in the interactions [19–30]. 4.1 A GeV/c 22Ne and 4.5 A GeV/c ( 4He, 12C, 16O, and 28Si) from Dubna Synchrophasotron

Multisource Thermal Model

Results and Discussions

A GeV A-Em C

Conclusion