Effects of spreading widths upon the direct nuclear reaction continuum

Abstract

Simple concepts which can be directly applied to measurements of resonances and the accompanying continua have been studied. Pickup reaction spectra leading to hole states in the continuum were found to give an understanding of the excitation energy dependence of resonance damping and the concurrent rise of "background" continuum states. When these hole resonances are parametrized in terms of the shell model, they can be used to predict the energy dependence of the damping of more complex resonances, such as collective particle-hole excitations in the inelastic scattering spectra. Furthermore, it is proposed that part of the background continuum in pickup spectra is the semidirect excitation of the 2h-1p states, the density of which determines both the nuclear damping width and the continuum cross section.NUCLEAR REACTIONS $^{208}\mathrm{Pb}(^{3}\mathrm{He}, \ensuremath{\alpha})$, $E=75$ MeV, $^{209}\mathrm{Bi}(p, d)$, $E=62$ MeV; calculated continuum cross sections in a direct reaction.