We discuss calculations of total reaction cross sections between complex nuclei, ${\sigma }_R,$ using optical limit and few-body Glauber models in which the free nucleon-nucleon cross sections ${\sigma }_{\mathrm{NN}}$ are replaced by their (reduced) values in the nuclear medium. This replacement lowers ${\sigma }_R$ by at most a few percent when ${\sigma }_{\mathrm{NN}}$ 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 ${\sigma }_R$ 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, ${\sigma }_{-2n}.$ We show that use of an in-medium ${\sigma }_{\mathrm{NN}}$ raises ${\sigma }_{-2n}$ for ${}^6\mathrm{He}$ but lowers it for ${}^{11}\mathrm{Li},$ because of their different halo sizes.

• Received 18 October 2001

DOI:https://doi.org/10.1103/PhysRevC.65.044617