Systematics of intermediate-energy single-nucleon removal cross sections

There is now a large and increasing body of experimental data and theoretical analyses for reactions that remove a single nucleon from an intermediate-energy beam of neutron- or proton-rich nuclei. In each such measurement, one obtains the inclusive cross section for the population of all bound final states of the mass $A-1$ reaction residue. These data, from different regions of the nuclear chart, and that involve weakly and strongly bound nucleons, are compared with theoretical expectations. These calculations include an approximate treatment of the reaction dynamics and shell-model descriptions of the projectile initial state, the bound final states of the residues, and the single-particle strengths computed from their overlap functions. The results are discussed in the light of recent data, more exclusive tests of the eikonal dynamical description, and calculations that take input from more microscopic nuclear structure models.

Figure 1

Compilation of the computed ratios $R_s$ of the experimental and theoretical inclusive one-nucleon-removal cross sections for each of the projectile nuclei indicated. $R_s$ is shown as a function of the parameter $\Delta S$, used as a measure of the asymmetry of the neutron and proton Fermi surfaces. The red points are for neutron-removal cases and the blue points those for proton removal. The solid (black) squares, deduced from electron-induced proton knockout data, are identical to the earlier compilation of Ref. [5].