Angular distributions of γ-rays from four resonances of the55Mn(p, γ)56Fe reaction

Abstract

Four resonances in the55Mn(p, γ)56 Fe reaction at the centre-of-mass proton beam energy E P CM =1320, 1504, 1508 and 1649 keV were studied. Angular distributions for some strong γ-rays following the radiative decay of the resonances were measured and analysed in terms of the channel-spin formalism. Spin-parity assignmentI r π =3+, 4+ and 3+ was acquired for the 1320, 1504 and 1649 keV resonances, respectively. No definite assignment was established for the 1508 keV resonance and the resonance is assumed to be a very tight multiplet. Analysis of primary transitions to bound states of the Fe final nucleus permited us to assign these states. The 2+, 2+, 2+, 6+ and 4+ assignments were ascribed to the states at excitation energyE x =5705, 5303, 4738, 4692 and 4658 keV, respectively, while for the 5132 keV state ambiguous assignment 3+ or 4+ was found. Multipole mixing ratioδ was established for some primaries. The coupling of angular momenta of proton and target nucleus in the formation of the 3+ resonances was also roughly discussed.