Different seniority states of 119-126Sn isotopes: shell-model description

In the present work, available experimental data up to high-spin states of Sn119-126 isotopes with different seniority (v), including v = 4, 5, 6, and 7, are interpreted with the shell model, by performing shell-model calculations in the 50-82 valence shell composed of 1g(7/2), 2d(5/2), 1h(11/2), 3s(1/2), and 2d(3/2) orbitals. The results are compared with the available experimental data. These states are described in terms of broken neutron pairs occupying the h(11/2) orbital. Possible configurations of seniority isomers in these nuclei are discussed. The breaking of three neutron pairs is responsible for generating high-spin states. The isomeric states 5(-), 7(-), 10(+), and 15(-) of even Sn isotopes, and isomeric states 19/2(+), 23/2(+), 27/2(-), and 35/2(+) of odd Sn isotopes, are described in terms of different seniority. For even Sn isotopes, the isomeric states 5(-), 7(-), and 10(+) are due to seniority v = 2; the isomeric state 15(-) is due to seniority v = 4, and, in the case of odd Sn isotopes, the isomeric states 19/2(+), 23/2(+), and 27/2(-) are due to seniority v = 3, and the isomeric state 35/2(+) in Sn-123 is due to seniority v = 5. These are maximally aligned spins, which involve successive pair breakings in the nu(h(11/2)) orbital.