Effects of deformation and neutron-proton pairing on the Gamow-Teller transitions for $^{24,26}\mathbf{Mg}$ in a deformed quasiparticle random-phase approximation

Effects of deformation and neutron-proton pairing on the Gamow-Teller transitions for ${}^{24, 26}{Mg}$ in a deformed quasiparticle random-phase approximation

Eunja Ha and Myung-Ki Cheoun

Phys. Rev. C 94, 054320 – Published 21 November 2016

Abstract

We investigate effects of neutron-proton ( $n p$ ) pairing correlations on the Gamow-Teller (GT) transition of ${}^{24, 26}{Mg}$ by explicitly taking into account deformation effects. Our calculation is performed by a deformed quasiparticle random phase approximation (DQRPA) which includes the deformation at the Bardeen-Cooper-Schrieffer and RPA stage. In this paper, we include the $n p$ pairing as well as neutron-neutron ( $n n$ ) and proton-proton ( $p p$ ) paring correlations to the DQRPA. Our new formalism is applied to the GT transition of well-known deformed Mg isotopes. The $n p$ pairing effect is found to affect more or less the GT distribution of ${}^{24}{Mg}$ and ${}^{26}{Mg}$ . But the deformation effect turns out to be much larger than the $n p$ paring effect because the Fermi surfaces smear more widely by the deformation rather than the $n p$ pairing correlations. Correlations between the deformation and the $n p$ pairing effects and their ambiguities are also discussed with the comparison to experimental GT strength data by triton and ${}^{3}{He}$ beams.