Investigation of⁵⁵Co Levels with the⁵⁴Fe(p, γ)⁵⁵Co Reaction II. Spins and Lifetimes

Abstract

The Doppler-shift attenuation (DSA) measurements of 7-rays performed on five S4Fe(p, Y ) ~~C O resonances yielded mean lifetimes of 20 levels in ''CO below 5.5MeV, seven of them for the first time. Angular distribution measurements were carried out on 17 j4Fe(p, 7 ) 5 5 C 0 resonances in the energy range E, = 1.1-2.3 MeV. The analysis of the angular distributions along with the present DSA and available literature data lead to the following unique spin and parity assignments for four bound states: 512-(E, = 2659 keV), 512-(37251,312-(4164) and 512' (4548). The spin of the 3563 keV state was found to be 3/2. The unique spin values of eight resonance states were determined. The present results are compared with recent shell-model calculations.