Relativistic Effects in Simulations of the Fragmentation Process with the Microscopic Framework

Tomoyuki Maruyama, Toshiki Maruyama, Koji Niita

Published 1995-07-28, updated 1995-10-02Version 5

We simulate the fragmentation processes in the \CaCa collisions at the bombarding energy 1.05 GeV/u using the Lorentz covariant RQMD and the non-covariant QMD approaches, incorporated with the statistical decay model. By comparing the results of RQMD with those of QMD, we examine the relativistic effects and find that the multiplicity of the $\alpha$ particle after the statistical decay process is sensitive to the relativistic effects. It is shown that the Lorentz covariant approach is necessary to analyze the fragmentation process even at the energy around \Elab = 1 GeV/u as long as we are concerned with the final observables of the mass distribution, particularly, the light fragments around $A = 3 \sim 4$.