Xe isotopes near mass $A\sim 130$ region, which exhibit features of O(6) symmetry at low energy and the backbending at high spins, are studied in the shell model framework. The monopole and quadrupole pairing plus quadrupole-quadrupole interaction is employed as an effective interaction. As for single-particle levels, the ${1d}_{3/2},$ ${0h}_{11/2},$ ${2s}_{1/2}$ orbitals are taken into account for neutrons and the ${1d}_{5/2},$ ${0g}_{7/2}$ orbitals for protons under the assumption of $N=Z=64\mathrm{}$ subshell closure. The calculation reproduces the experimental energy levels of high-spin states as well as low-lying states well. This is the first successful microscopic description of the backbending in this mass region. The shell model states are examined in pair-truncated models. The analysis shows the alignment of two ${0h}_{11/2}$ neutrons at high spins.

• Received 30 December 2001

DOI:https://doi.org/10.1103/PhysRevC.65.054317