First experimental determination of the radiative-decay probability of the 3 1 ? state in 12C for estimating the triple alpha reaction rate in high temperature environments

摘要

The triple alpha reaction is one of the most important reactions in the nuclear astrophysics. However, its reaction rate in high temperature environments atT9>2 was still uncertain. One of the major origins of the uncertainty was that the radiative-decay probability of the31?state in12C was unknown. In the present work, we have determined the radiative-decay probability of the31?state to be1.3?1.1+1.2×10?6by measuring the1H(12C,12Cp) reaction for the first time, and derived the triple alpha reaction rate in high temperature environments from the measured radiative-decay probability. The present result suggests that the31?state noticeably enhances the triple alpha reaction rate although the contribution from the31?state had been assumed to be small.