Evidence for chiral symmetry breaking in 140Eu ?

High spin states in 140Eu were populated following the reaction 92Mo(51V,2pn) at a beam energy of 205 MeV by the ESTU accelerator at the Wright Nuclear Structure Laboratory, Yale University. A total of 5 bands and 69 transitions were assigned to 140Eu . The assignments were based on K α x-ray coincidences and on excitation function measurements. γ-γ and γ-γ-γ coincidence matrices were created. Directional correlation of oriented states analysis, angular distributions, and Compton asymmetry measurements were performed and B(M1)/B(E2) branching ratios were extracted. The band assignments and structures are discussed in terms of the rotational model and interpreted following a series of cranked shell model and total Routhian surface calculations. In particular, two pairs of bands, one pair based on the πh 11/2 -νh 11/2 configuration, the other based on the π(g 7/2 ,d 5/2 )-νh11/2 configuration, are identified. These bands show some features expected of either chiral partners or shape coexistence, based on triaxial shapes with γ∼±25 deg. Further measurements are required to distinguish between these two possibilities