OBLATE BANDS IN DOUBLY ODD LA-134

The band structures of the doubly odd La-134 nucleus have been investi gated using the Cs-133(alpha, 3n)La-134 reaction at a beam energy of 4 0 MeV. Altogether six bands have been established, of which details of the yrast band were only known from earlier works. A negative parity oblate band has also been observed in this nucleus. The observed level properties of the members of the yrast band have been compared with t heoretical calculations performed within the Particle Rotor Model (PRM ) with axially symmetric core. The experimental branching ratios, B(M1 )/B(E2) values and mixing ratios of the transitions in the yrast band are well reproduced by PRM, assuming an axial oblate core. A cranked s hell model calculation has been carried out for the proposed bands. (C ) 1998 Elsevier Science B.V.