Effects of the in-mediumNNinteraction on total reaction and neutron removal cross sections

Abstract

We discuss calculations of total reaction cross sections between complex nuclei, ${\ensuremath{\sigma}}_{R},$ using optical limit and few-body Glauber models in which the free nucleon-nucleon cross sections ${\ensuremath{\sigma}}_{\mathrm{NN}}$ are replaced by their (reduced) values in the nuclear medium. This replacement lowers ${\ensuremath{\sigma}}_{R}$ by at most a few percent when ${\ensuremath{\sigma}}_{\mathrm{NN}}$ is determined from the local matter density in each overlapping volume element of the significant projectile-target trajectories. This relatively small effect contrasts with reductions of about 10% in ${\ensuremath{\sigma}}_{R}$ reported by Xiangzhou et al., who assume a global value for the matter density throughout the interaction region. For two-neutron halo nuclei, we investigate the significance of these in-medium effects for the neutron-removal cross sections, ${\ensuremath{\sigma}}_{\ensuremath{-}2n}.$ We show that use of an in-medium ${\ensuremath{\sigma}}_{\mathrm{NN}}$ raises ${\ensuremath{\sigma}}_{\ensuremath{-}2n}$ for ${}^{6}\mathrm{He}$ but lowers it for ${}^{11}\mathrm{Li},$ because of their different halo sizes.