The nucleon-pair approximation for nuclei from spherical to deformed regions
Abstract
In this paper we model low-lying states of atomic nuclei in the nucleon-pair approximation of the shell model, using three approaches to select collective nucleon pairs: the generalized seniority scheme, the conjugate gradient method, and the Hartree-Fock approach. We find the collective pairs obtained from the generalized seniority scheme provides a good description for nearly spherical nuclei, and those from the conjugate gradient method or the Hartree-Fock approach work well for transitional and deformed nuclei. Our NPA calculations using collective pairs with angular momenta 0, 2, and 4 (denoted by pairs) reproduce the nuclear shape evolution in the isotones, Ca, Ti, Cr, and Fe, and yield good agreement with full configuration-interaction calculations of low-lying states in medium-heavy transitional and deformed nuclei: Ti, Cr, Cr, Fe, Zn, Ge, Mo, and Xe. Finally, using the -pair approximation we describe low-lying states of Ba, cases difficult to reach by conventional configuration-interaction methods.
Cite
@article{arxiv.2012.09560,
title = {The nucleon-pair approximation for nuclei from spherical to deformed regions},
author = {G. J. Fu and Calvin W. Johnson},
journal= {arXiv preprint arXiv:2012.09560},
year = {2021}
}