HIGH-SPIN STATES IN ND-137 - A LARGE VARIETY OF COLLECTIVE ROTATIONS

The high-spin structure of Nd-137 has been studied through the Pd-110( Si-30,3n) and the Sb-123(F-19,5n) reactions at beam energies of 125 an d 97 MeV, respectively, A very complex level scheme has been establish ed up to spin 97/2(+) and 23.9 MeV of excitation energy. Regular bands are observed at high-spin, consisting of either M1 and E2 crossover t ransitions, or of stretched M1 or E2 transitions. Calculations have be en performed in the framework of the interacting boson-fermion model w ith broken pairs for the relatively strong Delta I = 1 regular structu res observed above spins 27/2(-) and 31/2(-), which are well described by the (nu h(11/2))(3) and nu h(11/2)x(pi h(11/2))(2) configurations, respectively. (C) 1997 Elsevier Science B.V.