Nucleon scattering to the continuum in terms of the two-fermion theory of multistep direct reactions

Cross sections of the (p,xp) reaction on Nb-93 were measured at an incident energy of 26.5 MeV and analysed together with the existing data for nucleon scattering between 18 and 26 MeV. The (p,p') and (n,n') emission spectra and angular distributions have been described consistently in the framework of the two-fermion multistep direct theory of Feshbach, Kerman and Koonin, We have confirmed the predictions following our earlier analyses that the strength of the effective nucleon-nucleon interaction does not depend on the reaction channel provided that all pre-equilibrium reactions are included. The latter requires allowing for the giant resonances in continuum from the energy-weighted sum rules. The method applied avoids double-counting of collective and onestep direct excitations. (C) 1998 Elsevier Science B.V.