Polarization factors and their effects on the rotational gyromagnetic ratio

Abstract

The effect of the polarizations on the collective gyromagnetic ratio (g R ) has been investigated in detail using the Rotational Invariant Quasiparticle Phonon Nuclear Model (RI-QPNM). The model includes an axially symmetric mean-field potential, monopole pairing, spin-dependent residual interactions, and the restoration forces determined according to Pyatov’s prescription for rotational invariance. The restoration of the rotational symmetry gives a solution at the zero energy associated with the rotational branch of nucleonic motion, allowing us to obtain the g R -factors of the core. The remaining solutions lead to the appearance of configuration mixing in the excitation spectrum of the odd-mass deformed nucleus. The configuration mixing quenches both spin and angular momentum matrix elements and affects the contribution of the odd particle to the g R . It has been demonstrated that the polarization factors associated with the ΔK = 1 matrix elements are essential to achieve quantitative agreement with the experimental data. It has also been shown that the general assumption for core polarization, i.e., g s e f f ≈ 0.6 g s f r e e , is insufficient to explain the experimental data.