BACKBENDING AND BREAKING OF AXIAL SYMMETRY IN THE YRAST BANDS OF XE114-130 ISOTOPES

The quadrupole deformation parameter beta(2), and energies of yrast st ates have been calculated in the microscopic frameworks, using the qua drupole-quadrupole-plus-pairing model of a two-body interaction for th e even-even isotopic mass chain of xenon isotopes. Results obtained in dicate that ground-state deformation systematics are satisfactorily re produced and there is a breaking of axial symmetry as Eve move along t he yrast states. Besides this, the observed backbending in some of the se isotopes is explained in terms of the partial rotational alignment of a pair of neutrons in the (1h(l1/2))(nu) orbit. [S0556-2813(98)0061 0-4].