Energy dependence of the reduced single-particle strength for strongly-bound proton removal on 16C

Abstract

Experimental data on the strongly-bound one-proton knockout from 16C at intermediate and high energies have recently been measured at NSCL and GSI, respectively. This is the first case that strongly-bound valence-nucleon knockout from weakly-bound nuclei was measured at both intermediate and high energies on composite nuclear targets. Based on these data, the eikonal model is employed to study the energy dependence of the reduction factor Rs, defined as the ratio of the experimental and theoretical cross sections, for the strongly-bound proton knockout from 16C. The Rs deduced at high energy [Rs = 0.40(1)] is larger than that extracted at intermediate energy [Rs = 0.30(3)], but is relatively small compared to the Rs's obtained for weakly-bound nucleon knockout(Rs ∼ 1) and well-bound nucleon knockout(Rs ∼ 0.6). A scaled Rs value of 0.32(1) for the high energy case is obtained after considering the possible uncertainties in the experimental data. It suggests that, if the scaled Rs is reliable, measurements using high-energy beams could not resolve the spectroscopic strength reduction problem and the strong isospin asymmetry dependence of the Rs persists at high energies.