The 58Ni(p, α) reaction mechanism through a study of the analyzing power

Abstract

Analyzing powers of the 58Ni(p, α) reaction at E p = 22 and 72 MeV have been calculated for transitions to the ground state of 55Co and to excited states in the continuum. DWBA calculations have been performed with both the α knock-out and triton pick-up models. The analyzing power at 72 MeV in the continuum was calculated with the statistical multistep direct theory. It is found that while the g.s. transition is dominated by the triton pick-up process, the analyzing power in the continuum can only be reproduced by an α knock-out mechanism. Some general considerations on the interplay between these two mechanisms and on the consistency with results obtained in the past with semiclassical preequilibrium models are made.