Nucleon-induced preequilibrium reactions in terms of the quantum molecular dynamics.

Abstract

The preequilibrium (nucleon-in, nucleon-out) angular distributions of $^{27}\mathrm{Al}$, $^{58}\mathrm{Ni}$, and $^{90}\mathrm{Zr}$ have been analyzed in the energy region from 90 to 200 MeV in terms of the quantum moleculear dynamics theory. First, we show that the present approach can reproduce the measured (p,${\mathit{xp}}^{\ensuremath{'}}$) and (p,xn) angular distributions leading to continuous final states without adjusting any parameters. Second, we show results of a detailed study of the preequilibrium reaction processes, the stepwise contributions to the angular distribution, comparisons with the quantum-mechanical Feshbach-Kerman-Koonin theory, and the effects of momentum distribution and surface refraction/reflection to the quasifree scattering. Finally, the present method was used to assess the importance of multiple preequilibrium particle emission as a function of projectile energy up to 1 GeV. \textcopyright{} 1996 The American Physical Society.