Ground-state proton decay of Br69 and implications for the se68 astrophysical rapid proton-capture process waiting point

Abstract

We report on the first direct measurement of the proton separation energy for the proton-unbound nucleus Br69. Bypassing the Se68 waiting point in the rp process is directly related to the 2p-capture rate through Br69, which depends exponentially on the proton separation energy. We find a proton separation energy for Br69 of Sp(Br69)=-785-40+34keV; this is less bound compared to previous predictions which have relied on uncertain theoretical calculations. The influence of the extracted proton separation energy on the rp process occurring in type I x-ray bursts is examined within the context of a one-zone burst model. © 2011 American Physical Society.