Gamow-Teller transitions in magic nuclei calculated by the charge-exchange subtracted second random-phase approximation

Abstract

The Gamow-Teller (GT) transitions in four magic nuclei, $^{48}\mathrm{Ca}, ^{90}\mathrm{Zr}, ^{132}\mathrm{Sn}$, and $^{208}\mathrm{Pb}$, are studied using a self-consistent Hartree-Fock (HF) plus charge-exchange subtracted second random-phase approximation (SSRPA) model with several Skyrme energy density functions (EDFs). These calculations show that SSRPA improves systematically the description of main GT strength distributions in terms of the excitation energy and the peak height. The quenching factors are evaluated to be 13--20% of the Ikeda sum rule for $^{48}\mathrm{Ca}, ^{90}\mathrm{Zr}$, and $^{132}\mathrm{Sn}$, due to the couplings to two-particle--two-hole (2p-2h) configurations. Also examined are the effects of tensor interactions on the excitation energies and the quenching factors of GT strength distributions.