Microscopic Description of (p, n) Reactions at Intermediate Energies

Abstract

Recently,(p, n) reactions at intermediate proton energies (Ep ≳ 100 MeV) have turned out to be a fruitful tool for studying charge-exchange excitations of nuclei, in particular, in the spin-isospin channel. Thus, the Gamow — Teller resonance (GTR) was discovered and the quenching of the integral strength of spinisospin transitions with a small momentum transfer in the low-energy range of the excitation spectrum (0 ≤ Ex ≤ 30 MeV) was established[1]. To obtain a quantitative estimate of the quenching factor in the continuous spectrum region, it was necessary to develop a microscopic approach for the description of observed inclusive neutron spectra and separation of contributions of various multipolarities. First estimates of a background below the GTR were made in papers[2] without taking into account the effective interactions of guasiparticles. Further development of this model and detailed calculations for 90Zr are given in ref.[3]. Analogous calculations by the Hartree-Fock method with the Skyrme interactions were carried out in ref.[4]. We have developed a microscopic model[5] for the description of angular distributions for individual excitations and inclusive spectra of neutrons, which differs from the above-mentioned approaches, mainly, by the method of structure calculations.