Triaxial Shape,Signature Splitting,and Shape Coexistence in 127,129,131Nd

Signature splitting and shape coexistence at high spin in the neutrondeficient nucleus ¹²⁹Nd are investigated with the configuration-dependent cranked Nilsson-Strutinsky approach. The calculatedbands are compared with the observed signature partner bands and very goodagreement results at high spin are obtained. The observed deformed bands are confirmed as normal and highly deformed and their properties are explained theoretically. Terminating states in ¹²⁹Nd and other terminations are predicted. There is shape coexistence within the same configuration from low-spin statesto high-spin states. Possible normal and highly deformed bands withrotation around the intermediate principal axis in several interestingconfigurations of ¹²⁹Nd are discussed. The experimental results for ¹³¹Nd are simply discussed and the calculated bands are in goodagreement with observed bands at high spin. Triaxial shapes in ¹²⁷Nd with a triaxial deformation of γ～-12^º are predictedand should be observed experimentally. The value of negative γ of π(h_11/2)⁴ν(h_11/2)⁷ configuration increases with neutron number increasing in ^127,129,131Nd. The triaxial shape evolutions with neutron number increasing in ^127,129,131Nd and in ^{126,128,130,132}Pr are explained by the strong driving force ofspecified single particle orbitals towards to triaxial shape.