Signature splitting inversion and backbending in 80Rb

High-spin states of 80Rb are studied via the fusion-evaporation reactions 65Cu+19F, 66Zn+18O, and 68Zn+16O with the beam energies of 75 MeV, 76 MeV, and 80 MeV, respectively. Twenty-three states with twenty-eight γ transitions are added to the previously proposed level scheme, where the second negative-parity band is significantly pushed up to spins of 22^- and 15^- and two sidebands are built on the known first negative-parity band. Two successive band crossings with frequencies 0.51 MeV and 0.61 MeV in the α = 0 branch as well as another one in the α = 1 branch of the second negative-parity band are observed. Signature inversions occur in the positive-parity and first negative-parity bands at the spins of 11 and 16, respectively. The signature splitting is seen obviously in the second negative-parity band, but the signature inversion is not observed. It is also found that the structure of the two negative-parity bands is similar to that of its isotone 82Y. Signature inversion in the positive-parity yrast band with configuration πg_9/2⊠- νg_9/2 in this nucleus is discussed using the projected shell model.