Low-spin signature inversion in the nh9/2 vi13/2 oblate band of Tl190

High-spin states in Tl190 have been studied experimentally by using the Gd160(Cl35,5n) fusion-evaporation reaction at beam energies of 167 and 175 MeV. A rotational band built on the nh9/2-i13/2 configuration with oblate deformation has been established for Tl190. Spin values are assigned by adopting the results from a-Y decay work for Bi194 found in the literature. With the configuration and spin-parity assignments, the low-spin signature inversion has been revealed for the nh9/2vi13/2 oblate band in Tl190. It is the first experimental observation of low-spin signature inversion for a band associated with the oblate Nh9/2aVi13/2 configuration. The low-spin signature inversion for the oblate Nh9/2vi13/2 band can be interpreted by the two-quasiparticle-plus- rotor model including a J-dependent p-n residual interaction.