Investigation of Gamow–Teller strength of ¹⁸⁶Hg within deformed pn-QRPA

Recently, the total absorption gamma spectroscopy technique was used to determine the Gamow-Teller (GT) distribution of β-decay of ¹⁸⁶Hg. It was concluded that the best description of the measured data was obtained with dominantly prolate components for both parent ¹⁸⁶Hg and daughter ¹⁸⁶Au. Motivated by the recent findings, we investigate the effect of nuclear deformation on the energy distribution of the GT strength of the decay of ¹⁸⁶Hg into ¹⁸⁶Au within the framework of proton-neutron quasiparticle random phase approximation (pn-QRPA) based on the deformed Nilsson potential. To do the needful, we first calculate the energy levels and shape prediction of ¹⁸⁶Hg within the interacting boson model. The computed GT strength distribution satisfied the model-independent Ikeda sum rule 100% (99.98%) for the prolate (oblate) case. Based on the strength distributions, the deformed pn-QRPA model with separable interaction prefers a prolate shape for the ground state of ¹⁸⁶Hg and supports the shape coexistence for this nucleus. (author)