Proton and neutron knockout from 36Ca

Abstract

The cross sections for single-nucleon knockout from Ca-36 on a Be-9 target at 70 MeV/nucleon were measured to be sigma(exp)(-p) = 51.1 +/- 2.6 mb for proton knockout and sigma(exp)(-n) = 5.03 +/- 0.46 mb for neutron knockout. The spectroscopic factors and orbital angular momenta of the neutrons and protons removed from Ca-36, leading to bound A = 35 residues, were deduced by comparison of the experimental cross sections and longitudinal- momentum distributions to those calculated in an eikonal reaction theory, and found to be S(p, 1d(3/2)) = 0.79 +/- 0.04 and S(n, 2s(1/2)) = 0.23 +/- 0.02 (relative to independent-particle-model values and only including experimental contributions to the uncertainties). As found in previous knockout studies, the spectroscopic factor deduced for the deeply bound neutron was significantly reduced relative to shell-model calculations, a result at variance with dispersive optical model (DOM) extrapolations, which suggest a spectroscopic factor closer to 60% of the independent-particle-model value.

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