Polarization transfer measurements for C12(p→,n→)N12(g.s.,1+) at 296 MeV and nuclear correlation effects

Differential cross sections and complete sets of polarization observables are presented for the Gamow-Teller C12(p→,n→)N12(g.s.,1+) reaction at a bombarding energy of 296 MeV with momentum transfers q of 0.1 to 2.2 fm-1. The polarization transfer observables are used to deduce the spin-longitudinal cross section, IDq, and spin-transverse cross sections, IDp and IDn. The data are compared with calculations based on the distorted-wave impulse approximation (DWIA) using shell-model wave functions. Significant differences between the experimental and theoretical results are observed for all three spin-dependent IDi at momentum transfers of q O. 5 -1, suggesting the existence of nuclear correlations beyond the shell model. We also performed DWIA calculations employing random-phase approximation (RPA) response functions and found that the observed discrepancy is partly resolved by the pionic and -mesonic correlation effects.