beta decay of Mg-31: Extending the "island of inversion"
Maréchal, F × Balabanski, DL Borremans, D Daugas, JM de Oliveira Santos, F Dessagne, P Georgiev, G Giovinazzo, J Grévy, S Himpe, Pieter Jollet, C Matea, I Neyens, Gerda Perrot, F Poirier, E Roig, O Stanoiu, M Stodel, C Thomas, JC Turzó, K Yordanov, Deyan Caurier, E Nowacki, F Poves, A #
American physical soc
Physical Review C vol:72
The beta decay of Mg-31 has been investigated at GANIL. The ions were implanted in a silicon detector array surrounded by germanium gamma detectors. beta particles and subsequent gamma rays have been observed. The Mg-31 half-life has been measured (T-1/2 = 237 +/- 25 ms) in good agreement with previously reported values. The decay scheme of Mg-31 has been enriched with two new low-spin levels and seven new gamma transitions in Al-31. Most importantly, very weak feeding to the Al-31 ground and lowest excited states has been established. These results are compared to new shell-model calculations in the sd-fp valence space, using an interaction that was modified in order to reproduce the recently established low-energy level scheme of Mg-31. A good agreement for all observables is found, supporting the idea that Al-31 is outside and Mg-31 is inside the so-called "island of inversion."