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 π = 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.