Magnetic properties of K=1/2 states in deformed odd-mass nuclei

Abstract

A method for calculation of the ground-state magnetic moment, effective spin gyromagnetic factors and rotational decoupling parameter of the K = 1/2 states in deformed odd-mass nuclei has been described by using the concept of the Quasiparticle Phonon Nuclear Model (QPNM). The model includes a Woods-Saxon potential as a mean field with pairing correlations and the residual separable spin-spin force in both isovector and isoscalar channels. The method has been employed to investigate K = 1/2 ground-state magnetic properties of Er-169 Tm-167,Tm-169, and Yb-171 nuclei, as an example. It has been shown that two different quenched spin gyromagnetic factors, i.e., g(s)(z)(eff.) and g(s)(+)(eff.) have a significant effect on the magnetic properties of K = 1/2 states in odd-mass nuclei. Whereas the first one is occurred due to the interaction between the valence nucleon and I-pi K = 1(+)0 excitations of the core, second one is associated with the coupling of the valence nucleon to I-pi K = 1(+)1 excitations of the core. The observed magnetic moments and the phenomenological value of g(s)(z)(eff.) for considered odd-mass nuclei have been reproduced very well by the calculations. The role of the isoscalar and isovector interactions on the magnetic properties of K = 1/2 states in these nuclei has been also discussed. (C) 2019 Elsevier B.V. All rights reserved.