Effect of theα-nucleus potential on the28Si(α,p)31Preaction

Abstract

The differential cross section of the ${}^{28}\mathrm{Si}(\ensuremath{\alpha}{,p)}^{31}\mathrm{P}$ reaction for 26 MeV incident energy has been analyzed in the distorted wave Born approximation (DWBA) with zero and full-finite range using a deep and shallow optical, Michel and molecular potentials in the incident channel, and a usual optical model potential for proton in the final channel. The parameters of potential in the entrance channel are determined from the elastic scattering data. The calculations done with the deep optical and Michel potentials reproduce the structure of the angular distributions reasonably well, but fail to account for the absolute magnitudes by a few orders. The shallow optical one is satisfactory up to about ${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}=100\ifmmode^\circ\else\textdegree\fi{}.$ The molecular potential, on the other hand, reproduces both the absolute cross sections and the pattern of the angular distributions. Coupled-channels Born approximation calculations improve fits to the data over the DWBA predictions.