Evidence of octupole correlation in Se 79

Two opposite parity bands I and II with eight new parity changing transitions have been identified in Se79 using the fusion-evaporation reaction Ge76(Be9, α2n) at ELab≈31 MeV. The B(M1) and B(E2) rates of bands I and II as well as B(E1) values of the linking transitions between the two bands have been determined from lifetime measurements and are compared with reflection asymmetric triaxial particle rotor model calculations. The large B(E1)/B(E2) ratios and B(E1) transition rates indicate the existence of a strong octupole correlation in the Se79 nucleus. This is also supported by the calculated potential energy surface, based on the covariant density functional theory within the three-dimensional lattice approach, which is very soft for the octupole shape degree of freedom β30. Extracted values of the intrinsic dipole moments |D0| from the B(E1) rates for the lower spin states also indicate the octupole correlation in Se79.