Medium energy proton and helium-3 capture in light nuclei

Abstract

Since our initial report of unexpectedly strong capture of 40 and 80 MeV protons to highly excited states in 12C, 13N, and 28Si, the Ohio State—Indiana University Cyclotron collaboration has continued to investigate the characteristics of medium energy radiative capture reactions. Among these are the existence of 2hω giant resonances built on 1hω excited states, as well as 3hω resonances on 2hω states; and the striking similarities of angular distributions and analyzing powers for similar single‐particle transitions in closed‐subshell and neighboring closed‐subshell‐plus‐one‐proton nuclei. We have also been impressed with the generally good description of the γ0 and γ1 observations provided by a direct‐semi‐direct reaction picture toward the higher energies investigated. Recently, however, we have observed an anomalously strong capture in 7Be to a state which appears to require a multi‐step process to populate. Radiative capture of 3He particles has also been studied by our group over the past few mon...