Spin-alignment attenuation factors in mass 61–67 nuclei populated by ( α, n) and ( α, p) reactions

Abstract

Gamma-ray angular distributions for 39 E2 transitions in A = 61–67 nuclei, excited in ( α , n) or ( α , p) reactions, are collected from the literature and reduced to spin-alignment attenuation factors α 2 and α 4 . The validity of the prediction for α 2 from statistical compound nucleus reaction theory is investigated. Also the sensitivity of this prediction to the optical-model parameters is examined. The present data support the rule 0 ⩽ α 4 ⩽ α 2 , but contradict the assumption of a Gaussian shape for the population of magnetic substates.