Low-energy Gamow-Teller transitions in deformed N=Z odd-odd nuclei

Abstract

We have investigated the Gamow-Teller transitions from 22 Ne to 22 Na by applying the isospin projected antisymmetrized molecular dynamics combined with generator coordinate method. We have found that the GT strength from A Z(J π T ) = 22 Ne(0 + 1 1) is fragmented into two final states 22 Na(1 + 1,2 0), which belong to K = 0 and K = 1 bands constructed by a prolately deformed 20 Ne core with a S = 1 proton-neutron (pn) pair. Coupling of the intrinsic-spin of the pn pair with the core deformation play an important role in the GT fragmentation. The symmetry breaking in the intrinsic-spin rotation leads to the SU (4)-symmetry breaking of the N N pair and causes the GT fragmentation. We have compared the features of the GT transitions with those for 10 Be → 10 B and discuss the link of the SU (4)-symmetry and the GT fragmentation in the deformed systems.