Polarization transfer measurements for {sup 12}C(p-vector,n-vector){sup 12}N(g.s.,1{sup +}) at 296 MeV and nuclear correlation effects

Differential cross sections and complete sets of polarization observables are presented for the Gamow-Teller {sup 12}C(p-vector,n-vector){sup 12}N(g.s.,1{sup +}) reaction at a bombarding energy of 296 MeV with momentum transfers q of 0.1 to 2.2 fm{sup -1}. The polarization transfer observables are used to deduce the spin-longitudinal cross section, ID{sub q}, and spin-transverse cross sections, ID{sub p} and ID{sub n}. 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 ID{sub i} at momentum transfers of q > or approx. 0.5 fm{sup -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 {rho}-mesonic correlation effects.