Intermediate particle-core coupling in reflection asymmetric odd mass nuclei

A coupling scheme between a collective core, with quadrupole and octupole deformation, and a single-particle spin is proposed to describe the complex distribution of the negative and positive parity states in odd mass nuclei. The model is based on an axially symmetric quadrupole-octupole geometric Hamiltonian with an adjustable particle-core coupling, offering a wide range of spectroscopic structures. A specific instance of the model, involving a moderate coupling strength, is identified in ¹⁵¹ 151 Ce, ¹⁵³ 153 Nd, ²²³ 223 Ra and ²²⁵ 225 Th nuclei, respectively discussed in terms of energy levels and relevant electric transitions.