Rotational bands of Gd-156

High-spin states of Gd-156 have been studied by using the reaction Nd-150(C -13,alpha 3n). The groundstate band, gamma band, and octupole band have bee n extended up to 26(+), 16(+), and 21(-) states respectively. Gamma-ray bra nchings between E2 decays down the K = 1(-) band and E1 decays across to th e ground band are discussed on the basis of the Generalized Intensity Relat ions. It is found that the B(E1)/B(E2) ratios have the maximum value at the intermediate spin. This feature is quite similar to the the case of the lo west octupole K = O- band in U-238 and is not yet resolved. Moreover a new band in the spin range of(10, 11) less than or equal to I less than or equa l to (20, 21) was observed, whose gamma -rays turned out to be almost ident ical in energy to the ones found in the isotone Dy-158. (C) 2001 Elsevier S cience B.V. All rights reserved.