[Formula Presented] examined: New limit on the β-delayed three-proton branch

Abstract

We have remeasured the decay of [Formula Presented] with a setup sensitive to multiparticle decay branches and obtained a new limit of [Formula Presented] (99% C.L.) on the β-delayed three-proton branch between the isobaric analog state in [Formula Presented] and the ground state of [Formula Presented]. This a factor of 17 below the previously reported first observation of β-delayed three-proton emission [Formula Presented]. The limit on a possible [Formula Presented] branch to the first excited state in [Formula Presented] is [Formula Presented]. © 1999 The American Physical Society.