Optimized perturbation theory applied to the study of the thermodynamics and BEC-BCS crossover in the three-color Nambu–Jona-Lasinio model

The Nambu–Jona-Lasinio model with two flavors, three colors, and diquark interactions is analyzed in the context of optimized perturbation theory (OPT). Corrections to the thermodynamical potential that go beyond the large-Nc (LN) approximation are taken into account, and the region of the phase dia...

Full description

Saved in:
Bibliographic Details
Published in:Physical review. D 2017-09, Vol.96 (5), Article 056009
Main Authors: Duarte, Dyana C., Farias, R. L. S., Manso, Patrícia H. A., Ramos, Rudnei O.
Format: Article
Language:English
Subjects:
Approximation
Chemical potential
Color
Condensates
Critical point
Crossovers
Fluids
Mathematical analysis
Organic chemistry
Perturbation theory
Phase diagrams
Phase transitions
Quarks
Solid phases
Superfluidity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The Nambu–Jona-Lasinio model with two flavors, three colors, and diquark interactions is analyzed in the context of optimized perturbation theory (OPT). Corrections to the thermodynamical potential that go beyond the large-Nc (LN) approximation are taken into account, and the region of the phase diagram corresponding to intermediate chemical potentials and very low temperatures is explored. The simultaneous presence of both the quark-antiquark and diquark condensates can cause the system to behave as a fluid composed of a Bose-Einstein condensate (BEC) or a color superconductor one, in the form of a Bardeen-Cooper-Schrieffer (BCS) superfluid. The BEC-BCS crossover is then studied in the nonperturbative OPT scheme. The results obtained in the context of the OPT method are then contrasted with those obtained in the LN approximation. We show that there are values for the coupling constants related to quark-quark and quark-antiquark interactions where the corrections beyond LN brought by the OPT method can influence the behavior of the diquark condensate and the effective quark mass as a function of the baryon chemical potential. These changes in the behavior of the phase structure of the model modify the location of the critical point related to the phase structure as a whole of the model. Also, when we impose the color neutrality condition, our results show that the nature of the phase transition can change as well, shifting the ratio of the quark-antiquark and quark-quark interactions to higher values in the OPT case as compared to the LN approximation.
ISSN:2470-0010
2470-0029
DOI:10.1103/PhysRevD.96.056009