ROTATIONAL BAND STUCTURES IN W-171,W-172 - ASPECTS ON SIGNATURE PARTNERSHIP AT HIGH-SPIN

High-spin states of W-171,W-172 have been investigated using the react ion Nd-146 (Si-30,5n-4n) at a bombarding energy of 160 MeV. In W-171, four negative-parity and two(three) positive-parity bands have been es tablished. A favoured (-, -1/2) configuration based on the (-, +1/2) c onfiguration (E) coupled to the (+,1) configuration (AC) is suggested to be the nature of the continuation of the (-, -1/2) band above the A B crossing. This would be the first observation of the EAC configurati on. The positive-parity decay sequences in W-171 provide an interestin g extreme signature dependence for the interband M1 transition matrix elements, which is found to be well accounted for by theoretical expec tations. In W-172 four negative-parity bands are established besides t he positive-parity yrast sequence.