Polarization transfer measurements for ¹²C(p⃗,n⃗)¹²N(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 ¹²C(p⃗,n⃗)¹²N(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, ID_q, and spin-transverse cross sections, ID_p and ID_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_i at momentum transfers of q≳0.5 fm^-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 ρ-mesonic correlation effects.