Angular distributions of low-energy neutrons from 390-MeV/nucleon Ne+Pb collisions

Abstract

Multiplicity-selected angular distributions of low-energy neutrons from collisions of 390 MeV/nucleon Ne+Pb are peaked forward, in contrast to relatively flat distributions of protons from Ne+U. A model that includes both Coulomb repulsion and composite-fragment formation accounts for the neutron and proton distributions, and the dependence on nucleon energy of the n/p ratio of inclusive cross sections. This comparison casts doubt on the interpretation of the suppression of forward proton emission as a signal of collective flow.