High-lying Gamow-Teller excited states in the deformed nuclei, 76Ge, 82Se and N = 20 nuclei in the island of inversion by the Deformed QRPA (DQRPA)

Abstract

With the advent of high analysis technology in detecting the Gamow-Teller (GT) excited states beyond one nucleon emission threshold, the quenching of the GT strength to the Ikeda sum rule (ISR) seems to be recovered by the high-lying (HL) GT states. We address that these HL GT excited states result from the smearing of the Fermi surface by the increase of the chemical potential owing to the deformation within a framework of the deformed quasi-particle random phase approximation (DQRPA). Detailed mechanism leading to the smearing is discussed, and comparisons to the available experimental data on 76Ge, 82Se and N = 20 nuclei are shown to explain the strong peaks on the HL GT excited states.