The Multipolarity of γ-ray Absorption in ¹²C(γ, 3α) Reaction produced by (Li, p)γ-rays

Abstract

The mechanism of the ¹²C(γ, 3α) reaction for (Li, p)γ-rays has been estimated from a study of 576 stars in nuclear emulsions. By the analysis of the angular distributions and correlation of the α-particles, the multipolarity of the absorption process of (Li, p)γ-rays by the ¹²C nucleus can be explained by the mixture of two sorts of interaction E1 and E2. This result is consistent with Goward and Wilkins’ conclusion, but our experimental data of the angular distribution of the first α-particles show significant forward asymmetry contrary to their backward asymmetry.