Collective radial expansion in Au+Au reactions from 0.25 to 2 GeV/nucleon

Abstract

A nonthermal expansive component has recently been interpreted from the observed light fragment spectra in Au + Au collisions. We have used the BUU transport model to generate several different freezeout surfaces and applied a coalescence algorithm to approximate the complete final state. We vary the microscopic details leading to specific equations of state, reduce cross sections, and isolate the effect of compression on the spectra for protons and helium isotopes. We find a radial flow signal consistent with experiment in the energy range 0.25A to 1.15A GeV, but find it to be rather insensitive to the microscopic details of the model calculations. \textcopyright{} 1996 The American Physical Society.