High-spin states in 137Nd: A large variety of collective rotations

Abstract The high-spin structure of 137 Nd has been studied through the 110 Pd( 30 Si,3n) and the 123 Sb( 19 F,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 ΔI = 1 regular structures observed above spins 27 2 − and 31 2 − , which are well described by the (νh 11 2 ) 3 and νh 11 2 ⊗(πh 11 2 ) 2 configurations, respectively.