Two-proton removal from $^{44}$S and the structure of $^{42}$Si

Abstract

Newly-published $^{42}$Si gamma-ray spectra and a final-state-inclusive $^{42}$Si production cross section value, obtained in a higher-statistics intermediate-energy two-proton removal experiment from $^{44}$S, are considered in terms of the final-state-exclusive cross sections computed using proposed shell-model effective interactions for nuclei near N=28. Specifically, we give cross section predictions when using the two nucleon amplitudes of the two-proton overlaps $<^{42}$Si$ (J^π)\,|\,^{44}$S$>$ computed using the newly-proposed {\sc sdpf-mu} shell-model Hamiltonian. We show that these partial cross sections or their longitudinal momentum distributions should enable a less-tentative interpretation of the measured gamma-ray spectra and provide a more quantitative assessment of proposed shell-model Hamiltonians in this interesting and challenging region of the chart of nuclides.

4 pages, 2 figures