Detailed study of the decay of $$^{21}$$Mg

Abstract

AbstractBeta-delayed proton and gamma emission in the decay of $$^{21}$$ 21 Mg has been measured at ISOLDE, CERN with the ISOLDE Decay Station (IDS) set-up. The existing decay scheme is updated, in particular what concerns proton transitions to excited states in $$^{20}$$ 20 Ne. Signatures of interference in several parts of the spectrum are used to settle spin and parity assignments to highly excited states in $$^{21}$$ 21 Na. The previously reported $$\beta $$ β p$$\alpha $$ α branch is confirmed. A half-life of 120.5(4) ms is extracted for $$^{21}$$ 21 Mg. The revised decay scheme is employed to test mirror symmetry in the decay and to extract the beta strength distribution of $$^{21}$$ 21 Mg that is compared with theory.