Search for isobaric analogue states in ⁵⁷Co via the reaction⁵⁶Fe (p,y)⁵⁷Co

Abstract

The ⁵⁶Fe(P,Y) ⁵⁷Co reaction has been studied over the proton energy range of Eρ=3694-3855 keV. Four resonances were observed at Eρ=3720, 3727, 3774 and 3793 keV. Decay schemes were established for the four resonances, and angular distributions were measured at Eρ=3720, 3774 and 3793 keV. A Jπ=9/2⁺ has been assigned for the resonances at Eρ=3720 and 3727 keV, and Jπ = 5/2⁺ has been assigned for the resonances at Eρ=3774 and 3793 keV. In this work it was concluded that the two resonances at Eρ=3720 and 3727 keV (Eχ=9682 and 9689 keV) are fragments of an isobaric analogue state in ⁵⁷Co corresponding to the g₉/₂ at Ex=2455 keV in ⁵⁷Fe. Moreover, it was concluded that the two resonances t Eρ=3774 and 3793 keV (Eχ=9734 and 9753 keV) are two fragments of an isobaric analogue state in ⁵⁷Co corresponding to the d₅/₂ at Eχ=2506 keV in ⁵⁷Fe. Levels at Eχ=4586 and 4675 keV in ⁵⁷Co are indentified as the antianalogue states (T<) corresponding to the g₉/₂ and d₅/₂ isobaric analogue states respectively.