Study of isobaric analogue resonances in f-p shell nuclei: A unified-model description

Spectroscopic factors as well as parentage coefficients for collective J i π = 2 1 +, 3 1 − and 4 1 + states have been obtained for N = 29 nuclei and 59Ni via (τ, d p ) reactions through isobaric analogue resonances (IAR). In the framework of a unified-model calculation, treating the one-neutron core-coupling ( N = 29) and three-neutron core-coupling as well as pure three-neutron shell-model calculations ( 59Ni), a description can be given for most of the observed phenomena (energies, spectroscopic factors, parentage coefficients on the J i π = 2 1 +, 3 1 −, 4 1 + levels). Some discrepancies remain, especially with respect to the description of the splitting of the 2 p 1 2 neutron single-particle state. A comparison with earlier calculations for the N = 29 nuclei is carried out. With respect to 59Ni, the three-particle-cluster effects are pointed out and an extensive comparison between both types of calculation and with experiment is made.