Ab initio calculations of Gamow-Teller strengths in the sd shell

Abstract

In the present work we perform a systematic shell-model study of Gamow-Teller transition-strength distributions in sd shell nuclei using ab initio effective interactions. The ab initio effective interactions are based on in-medium similarity renormalization-group and coupled-cluster effective interaction approaches. The aim of the present work is to test the predictive power of ab initio effective interactions by using the available experimental data of Gamow-Teller strength distributions in sd shell nuclei. We perform calculations for Ne20→F20, Na23→Mg23, Na23→Ne23, Mg24→Na24, Mg24→Al24, Mg25→Al25, Mg26→Na26, Mg26→Al26, Si26→Al26, Al27→Si27, Si28→P28, P31→Si31, and S32→P32 transitions. For comparison we also show the results obtained by using the phenomenological USDB Hamiltonian. The phenomenological USDB results of the Gamow-Teller (GT+ and GT-) strength distributions show reasonable agreements with the experimental data in comparison with the ab initio interactions. We also calculate the electron-capture reaction rates for Na23(e-,ν)Ne23 and Mg25(e-,ν)Na25 using ab initio and USDB interactions. © 2018 American Physical Society.