Deformed shell model calculations of half lives forβ+/EC decay and2νβ

Deformed shell model results for two-neutrino positron double-βdecay ofSe74

“…In the past, attempts have also been made for 106,108 Cd [16] and 130,132 Ba [17] nuclei. Prompted by this experimental interest, recently we [18] have carried out calculations for 78 Kr using the DSM by employing a modified Kuo interaction in ( 2 p 3/2 , 1 f 5/2 , 2 p 1/2 , 1 g 9/2 ) space. The predictions of DSM for 2ν e + DBD half-lives are close to those of QRPA and PHFB models.…”

“…To extend the study in Ref. [18] further, we have carried out DSM calculations for 2ν e + DBD half-lives for the 74 Se nucleus, and the results are reported in this brief report. We did not consider 64 Zn as spherical shell model is well suited [19] for the three nuclei 64 Zn, 64 Cu, and 64 Ni.…”

“…This model has also been used to study 2ν DBD transition-matrix elements for 76 Ge → 76 Se [28] with considerable success. More recently, in [18] we have applied DSM to study β-decay half-lives, Gamow-Teller (GT) distributions, electron capture rates, and 2ν e + DBD in 78 Kr. All these confirm that DSM generates good nuclear-wave functions for nuclei in the mass region A ∼ 64-80.…”

“…DSM is well established as a successful model for transitional nuclei (with A = 64-80) when sufficient intrinsic states are included in the band-mixing calculations; see Ref. [18] and references therein. By performing DSM calculations for the parent, daughter, and the intermediate odd-odd nucleus (here we need only the 1 + states) and then using the DSM wave functions, we calculate the σ τ − matrix elements in Eq.…”

“…1. Only prolate intrinsic states are considered in these calculations, and the oblate intrinsic states are ignored just as in the previous 78 Kr analysis [18] using DSM. The reason for neglecting the oblate states has been discussed in an earlier publication [36].…”