Photoreactions of 12C, 16O and 40Ca in self–consistent RPA theory. II. Unpolarized (γ, p) and (γ, n) angular distributions below pion threshold

The (γ, p), (γ, n) and inverse capture reactions in 12C, 16O and 40Ca below pion threshold have been analysed in the frame of a self-consistent RPA theory with a Skyrme force (Sk3). E1 and E2 transitions in LWA are present in the calculation. Thereby, EC linked by gauge invariance to the effective interaction are included in the predicted cross sections. Through an overall comparison with the available experimental data, we attain, in the present context, a good fit of data up to 80 MeV. The observed symmetric behaviour of (γ, p) and (γ, n) angular distributions is well reproduced. The rôle of nuclear correlations on the action of EC by gauge invariance is discussed.