Detailed study of the decay of ^21Mg

Beta-delayed proton and gamma emission in the decay of ^21Mg 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 ^20Ne. Signatures of interference in several parts of the spectrum are used to settle spin and parity assignments to highly excited states in ^21Na. The previously reported βpα branch is confirmed. A half-life of 120.5(4) ms is extracted for ^21Mg. The revised decay scheme is employed to test mirror symmetry in the decay and to extract the beta strength distribution of ^21Mg that is compared with theory.