Signature Inversion in the πh_(9/2) νi_(13/2) Oblate Band of ~(190)Tl

High spin states in 190 Tl have been studied experimentally using the 160 Gd( 35 Cl, 5n) fusion evaporation reaction at beam energies of 167—175 MeV. A rotational band built on the π h 9/2  ν i 13/2 configuration with oblate deformation has been established. Spin values have been firmly assigned to the π h 9/2  ν i 13/2 oblate band by combining the present in beam experimental results with the complementary α γ correlation measurements of 194 Bi α decay. With the configuration and spin parity assignments, the low spin signature inversion has been revealed for the π h 9/2  ν i 13/2 oblate band. It is the first experimental observation of low spin signature inversion for a band associated with the oblate π h 9/2  ν i 13/2 configuration. The low spin signature inversion could be interpreted in the framework of the quasiparticles plus rotor model including a J dependent proton neutron residual interaction.