Beyond Mean Field Description of the Gamow-Teller β+ Decay of Proton-Rich Kr Isotopes

We studied the influence of shape mixing on the Gamow-Teller β+ decay of the nucleus 74Kr using the complex Excited Vampir variational approach for the description of the ground state of the parent nucleus and the 1+ states in the beta window in the daughter nucleus 74Br. Within the same approach the Gamow-Teller strength distributions for the decay of the ground state and the lowest-excited states in the nucleus 72Kr to the 1+ states in the nucleus 72Br are obtained using a rather large model space and realistic effective interaction. The shape coexistence and mixing are consistently described for both the 0+ and 2+ states in the even-even parent nucleus and the 1+ states in the odd-odd daughter nucleus. The theoretical results for the Gamow-Teller strength distributions and the accumulated strengths are compared with the available data and predictions concerning the decay of the first excited 0+ and the yrast 2+ in the rp-process waiting point nucleus 72Kr are presented