Band termination in the shell model

The mechanism of band termination is discussed from the spherical shell model point of view, and the role of breaking nucleon pairs within a given j-shell configuration is stressed. Two main types of band terminations are discussed. In one type the band termination includes a sequence of states within an approximative seniority coupling scheme and therefore is smooth. In the other type the terminated state involves the breaking of one additional nucleon pair that results in a less smooth band termination. Band terminations in nuclei around 48Cr are calculated in the fp-shell model, and both types of band terminations are illustrated.