S-pairing in neutron matter: I. Correlated basis function theory

Adelchi Fabrocini, Stefano Fantoni, Alexey Yu Illarionov, Kevin Schmidt

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

S-wave pairing in neutron matter is studied within an extension of correlated basis function (CBF) theory to include the strong, short range spatial correlations due to realistic nuclear forces and the pairing correlations of the Bardeen, Cooper and Schrieffer (BCS) approach. The correlation operator contains central as well as tensor components. The correlated BCS scheme of [S. Fantoni, Nucl. Phys. A 363 (1981) 381], developed for simple scalar correlations, is generalized to this more realistic case. The energy of the correlated pair condensed phase of neutron matter is evaluated at the two-body order of the cluster expansion, but considering the one-body density and the corresponding energy vertex corrections at the first order of the Power Series expansion. Based on these approximations, we have derived a system of Euler equations for the correlation factors and for the BCS amplitudes, resulting in correlated nonlinear gap equations, formally close to the standard BCS ones. These equations have been solved for the momentum independent part of several realistic potentials (Reid, Argonne v14 and Argonne v8′) to stress the role of the tensor correlations and of the many-body effects. Simple Jastrow correlations and/or the lack of the density corrections enhance the gap with respect to uncorrelated BCS, whereas it is reduced according to the strength of the tensor interaction and following the inclusion of many-body contributions.

Original languageEnglish (US)
Pages (from-to)137-158
Number of pages22
JournalNuclear Physics A
Volume803
Issue number3-4
DOIs
StatePublished - May 1 2008

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Keywords

  • Nuclear cluster models
  • Nuclear forces
  • Nuclear matter
  • Nuclear pairing
  • Superfluidity

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

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