Reduction of stretched-magnetic-transition strengths by core polarization

Abstract

A second-order perturbative calculation is reported for core-polarization effects on the matrix elements 〈p−132d52; T, Jπ=4−|M4| 16Ocore; 0+〉 with T=0 and T=1 or the stretched-magnetic (M4) excitation in 16O. It is found that the matrix elements are reduced from the single-particle value by both first- and second-order correction terms with comparable magnitudes, and the reductions come mainly from the central part of the nucleon-nucleon interaction. The reduction of the strength observed in inelastic electron scattering experiments is well explained by the core polarization. The calculated results are quite consistent for two different sets of realistic interactions, the Paris potential and the Reid soft-core potential.