NUCLEAR PAIRING MODELS

P. MÖLLER and J. R. NIX Theoretical Division, Los Alamos National Laboratory, New Mexico 87545, USA
We calculate nuclear pairing gaps for nuclei throughout the periodic system in both the BCS and Lipkin-Nogami pairing models. The energy levels required for the calculations are obtained from the folded-Yukawa single-particle model for ground-state shapes obtained in the macroscopic-microscopic approach by minimizing the total potential energy with respect to epsilon_2 and epsilon_4 shape degrees of freedom. For both pairing models we study two proposed forms for the effective-interaction pairing gap that is used to determine the pairing-gap parameter G that enters directly into the pairing equations. By comparing the calculated pairing gaps to experimental odd-even mass differences we determine parameter values for the proposed forms of the effective-interaction pairing gap by least-squares minimization. These comparisons to data lead to a preferred form for the effective-interaction pairing gap and to values of its parameters for both the BCS and Lipkin-Nogami models. From this microscopic study we conclude that no explicit isospin dependence is required for the effective-interaction pairing gap that is used to determine the pairing-gap parameter G.
The text and the figures are available for download.
This manuscript has been assigned Los Alamos Preprint No LA-UR-01-1648.

Page by Peter Möller
moller@lanl.gov
created 2001 last modified 5 July 2012