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.
@article{arxiv.2405.01276,
title = {Detailed study of the decay of $^{21}$Mg},
author = {E. A. M. Jensen and S. T. Nielsen and A. Andreyev and M. J. G. Borge and J. Cederkäll and L. M. Fraile and H. O. U. Fynbo and L. J. Harkness-Brennan and B. Jonson and D. S. Judson and O. S. Kirsebom and R. Lică and M. V. Lund and M. Madurga and N. Marginean and C. Mihai and R. D. Page and Á. Perea and K. Riisager and O. Tengblad},
journal= {arXiv preprint arXiv:2405.01276},
year = {2024}
}
Comments
14 pages, 10 figures. This version includes the same content as the published, open-access version. In this version, details about the conditions during the experiment have been expanded (section 2), scattered claims and comments have been clarified and columns containing particle (lab) energies have been added to tables 1 and 2