Strength of J π = 1 + Gamow-Teller and isovector spin monopole transitions in double- β -decay triplets

Abstract

In this work we study systematically the energetics and intensity distributions of Gamow-Teller (GT±) and isovector spin monopole (IVSM±) transitions from the ground states of the pairs (76Ge, 76Se), (82Se, 82Kr), (100Mo, 100Ru), (116Cd, 116Sn), (128Te, 128Xe), (130Te, 130Xe), and (136Xe, 136Ba), of double-beta-decay initial and final nuclei, to the J pi = 1 + excited states of the intermediate odd-odd nuclei 76As, 82Br, 100Tc, 116In, 128,130I, and 136Cs. We use a proton-neutron quasiparticle random-phase approximation (QRPA) theory framework with the Bonn-A two-body interaction in large no-core single-particle valence bases. Our studies indicate that the GT − strength at the giant resonance (GTGR) region and the low-energy part of the IVSM − strength overlap, which could be of significance for the analyses of the (p,n) type of reaction experiments at and around the GTGR.