The ΔTz = + 1 Gamow-Teller excitation of N = 28 isotones

Abstract

Results of shell-model calculations of Gamow-Teller strength distributions are presented for 50Ti → 50Sc, 52Cr → 52V and 54Fe → 54Mn. The results support the previous shell-model estimates that a large fraction of Gamow-Teller strength is concentrated at low excitation energy in the daughter nuclei. The strength distributions are in fairly good agreement with those of forward-angle cross sections of T 0 + 1 isospin states of the intermediate-energy (p, p') reaction on N = 28 isotones. An estimate of quenching in the T 0 → T 0 + 1 τσ mode transition is attempted. Calculations are performed also for the first 2 + and 4 + parent states in the context of electron capture at the late stages of stellar evolution.