The high-spin behavior of Eu-153 nucleus has been investigated via the
Nd-150(Li-7,4n gamma) reaction. The level structures of the nucleus b
uilt on the 5/2(+) ground state and the 5/2(-) excited state have been
established up to spins 39/2(+) and 43/2(-), respectively, and are ob
served to be interleaved through strong El transitions. From the B(E1)
/B(E2) ratios of the high-spin region the intrinsic electric-dipole mo
ment is deduced and is found to be 0.181+/-0.007 e fm and beta(3) thus
obtained is similar to 0.03. The rotational features and magnetic mom
ents indicate that an octupole correlated deformation has developed wi
th the increasing spin. A theoretical study of the correlation between
the beta(3) and the band crossing frequency supports the conjecture o
f octupole deformation at high spin.