Study of nuclear correlation effects via C12(p→,n→)N12(g.s.,1+) at 296 MeV

Abstract We report measurements of the cross section and a complete set of polarization observables for the Gamow–Teller C 12 ( p → , n → ) N 12 ( g.s. , 1 + ) reaction at a bombarding energy of 296 MeV. The data are compared with distorted wave impulse approximation calculations employing transition form factors normalized to reproduce the observed beta-decay ft value. The cross section is significantly under-predicted by the calculations at momentum transfers q ≳ 0.5 fm −1 . The discrepancy is partly resolved by considering the non-locality of the nuclear mean field. However, the calculations still under-predict the cross section at large momentum transfers of q ≃ 1.6 fm −1 . We also performed calculations employing random phase approximation response functions and found that the observed enhancement can be attributed in part to pionic correlations in nuclei.