BCS-BEC crossover of neutron pairs in symmetric and asymmetric nuclear matter

Journal Article · Sat Dec 15 04:00:00 EST 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.76.064316· OSTI ID:21067973

Margueron, J ^[1]; Sagawa, H ^[2]; Hagino, K ^[3]

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1. Institut de Physique Nucleaire, Universite Paris-Sud, IN2P3-CNRS, F-91406 Orsay Cedex (France)
2. Center for Mathematical Sciences, University of Aizu, Aizu-Wakamatsu, 965-8580 Fukushima (Japan)
3. Department of Physics, Tohoku University, Sendai, e980-8578 (Japan)

We propose new types of density-dependent contact pairing interactions which reproduce the pairing gaps in symmetric and neutron matters obtained by a microscopic treatment based on realistic nucleon nucleon interaction. These interactions are able to simulate the pairing gaps of either the bare interaction or the interaction screened by the medium polarization effects. It is shown that the medium polarization effects cannot be cast into the usual density power law function of the contact interaction and require the introduction of another isoscalar term. The BCS-BEC crossover of neutron pairs in symmetric and asymmetric nuclear matters is studied by using these contact interactions. This work shows that the bare and screened pairing interactions lead to different features of the BCS-BEC crossover in symmetric nuclear matter. For the screened pairing interaction, a two-neutron BEC state is formed in symmetric matter at k{sub Fn}{approx}0.2 fm{sup -1} (neutron density {rho}{sub n}/{rho}{sub 0}{approx}10{sup -3}). In contrast, the bare interaction does not form the BEC state at any neutron density.

• OSTI ID: 21067973
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 6 Vol. 76; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASYMMETRY
BCS THEORY
BOSE-EINSTEIN CONDENSATION
NEUTRON DENSITY
NEUTRONS
NUCLEAR MATTER
NUCLEAR STRUCTURE
NUCLEON-NUCLEON INTERACTIONS
PAIRING INTERACTIONS
POLARIZATION