STUDY OF HIGH-SPIN STATES IN EU-150 AND EU-151

High-spin states in Eu-150,Eu-151 were populated by the Xe-136(F-19, x n)Eu-155-xn reaction. Extensive e gamma-, gamma gamma-measurements led to new level schemes of Eu-150,Eu-151. Most observed excitations are interpreted as quasi-rotational bands built on top of multi-p-h states . Enhanced E1 decays competing with E2 transitions indicate an octupol e instability of these nuclei at medium spin. Furthermore, a few negat ive parity bands of Eu-151 decay through large M1 interband transition s which are interpreted as rotations of a triaxial shape. The observed structures at high spin, especially for Eu-151, show the coexistence of axial and non-axial symmetric shapes.