Test for the shell-model-Weinberg treatment of the reaction15N(n,n′)15N* with a separable interaction

A modification of Weinberg's method in connection with the Born approximation was first employed by Ebenhöhet al. to describe the reaction¹⁵N(n, n′)¹⁵N^* using a delta-force as residual interaction. This method is now applied to the same reaction but using a surface-delta-interaction. For this separable interaction also the exact solution of the problem is presented. We were not interested in adjusting any parameters to obtain optimal agreement with experiment. Only the results of these two approaches are compared. The good agreement may give confidence in the application of the modified Weinberg method in connection with non-separable interactions.