Shell-Model Study of the N  28 Nuclei with Emphasis on High-Spin States

Abstract

High-spin states in the N ∼28 nuclei are studied in terms of the shell model within the f7/2n + f7/2n-1p3/2 configurations including the neutron excitations from the f7/2 shell. Strongly attractive proton-neutron interactions among the f7/2 nucleons play an important role for the high-spin states generated by the f7/2n-1p3/2 configurations. Agreement between the calculated and observed spectra of high spins in the N = 28 nuclei is very good. It is revealed that the high-spin states with relatively small excitation energies in the N ∼28 nuclei can be interpreted by the neutron excitations from the f7/2 to the upper orbits.