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 and 97 MeV, respectively, A very complex level scheme has been established 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 transitions, or of stretched M1 or E2 transitions. Calculations have been performed in the framework of the interacting boson-fermion model with broken pairs for the relatively strong Delta I = 1 regular structures 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.