2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/82589We simulate the fragmentation processes in the \alAu collisions at the bombarding energy 5 GeV/u using the simplified RQMD approach. The statistical decay calculation is connected to obtain the final state. >From the simulation we find that the residual nucleus created by this collision has a annular eclipse shape, and then expands more strongly to the transverse direction than to the beam-direction. Then the angular-distribution of the intermediate mass fragments has a sideward peak; this result explains the experimental result.6pages, Latex is used, 3 Postscript figures, gziped, tared and uuencode, are given after the text. They are also available by request from tomo@hadron05.tokai.jaeri.go.jpNuclear Theorytext