Nuclear pairing: Global trends and local fluctuations
We calculate nuclear pairing gaps for ground-state configurations for 8979 nuclei from {sup 16}O to A = 339 in the Lipkin-Nogami pairing model. The energy levels required for the calculation are obtained from the folded-Yukawa single-particular model for ground-state shapes obtained in the macroscopic-microscopic approach by minimizing the total potential energy with respect to {epsilon}{sub 2},{epsilon}{sub 4}, {epsilon}{sub 3} and {epsilon}{sub 6} shape degrees of freedom. We study the behavior of the calculated pairing gap {Delta} and the number-fluctuation constant {lambda}2 on neutron number N and proton number Z. We discuss alternative methods for comparing calculated pairing gaps to odd-even experimental mass differences and study the trends of the deviations between calculated and measured quantities versus N and Z. In particular we discuss the many non-smooth contributions to the so-called experimental pairing gap that is extracted from odd-even measured mass differences and the resulting difficulties that are present when these axe compared to calculated results. In recent years several studies have investigated whether nuclear pairing depends on neutron excess. Furthermore, any dependence on neutron excess is small compared to both the random and the correlated errors in the pairing gaps that are extracted from experimental odd-even mass differences. Therefore appropriate care is required before conclusions can be drawn from calculated and experimental quantities. We use our global calculations of nuclear pairing quantities as a basis for a discussion of what conclusions can be drawn about the accuracy of current pairing models and the behavior of nuclear pairing with neutron excess. We also suggest what new nuclear mass measurements would serve as useful tests of pairing models. To provide the most informative presentation of the trends of the quantities studied over the entire periodic chart we display several of our results in the form of color
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moller (P.) Scientific Computing and Graphics, Inc., Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 10175360
- Report Number(s):
- LA-SUB-94-102; ON: DE94017057; CNN: Contract 9-XG3-6295F-1; TRN: 94:016679
- Resource Relation:
- Other Information: PBD: 29 Dec 1993
- Country of Publication:
- United States
- Language:
- English
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