Reduced neutron spectroscopic factors when using potential geometries constrained by Hartree-Fock calculations

We carry out a systematic analysis of angular distribution measurements for selected ground-state to ground-state ($d,p$) and ($p,d$) neutron transfer reactions, including the calcium isotopes. We propose a consistent three-body model reaction methodology in which we constrain the transferred-neutron bound state and nucleon-target optical potential geometries using modern Hartree-Fock calculations. Our deduced neutron spectroscopic factors are found to be suppressed by $~30$% relative to independent-particle shell-model values, from ⁴⁰Ca through ⁴⁹Ca. The other nuclei studied, ranging from B to Ti, show similar average suppressions with respect to large-basis shell-model expectations. Our results are consistent with deduced spectroscopic strengths for neutrons and protons from intermediate-energy nucleon knockout reactions and for protons from (e,e'p) reactions on well-bound nuclei.