Role of two-flavor color superconductor pairing in a three-flavor Nambu--Jona-Lasinio model with axial anomaly

Abstract

The phase diagram of strongly interacting matter is studied within a three-flavor Nambu--Jona-Lasinio model, which contains the coupling between chiral and diquark condensates through the axial anomaly. Our results show that it is essential to include the 2SC phase in the analysis. While this is expected for realistic strange quark masses, we find that even for equal up, down, and strange bare quark masses, 2SC pairing can be favored due to spontaneous flavor-symmetry breaking by the axial anomaly. This can lead to a rich phase structure, including BCS- and BEC-like 2SC and CFL phases and new endpoints. On the other hand, the low-temperature critical endpoint, which was found earlier in the same model without 2SC pairing, is almost removed from the phase diagram and cannot be reached from the low-density chirally broken phase without crossing a preceding first-order phase boundary. For physical quark masses no additional critical endpoint is found.

12 pages, 10 figures, added appendix clarifying the relation to Ginzburg-Landau results, to appear in PRD

References in corpus (11)

• The order of the quantum chromodynamics transition predicted by the standard model of particle physics
• Color superconductivity in dense quark matter
• The QCD transition temperature: results with physical masses in the continuum limit II.
• Inhomogeneous phases in the Nambu-Jona-Lasino and quark-meson model
• New Critical Point Induced by the Axial Anomaly in Dense QCD
• Two lectures on color superconductivity
• Phase structure, collective modes, and the axial anomaly in dense QCD
• Vector interaction, charge neutrality and multiple chiral critical point structures
• Bound diquarks and their Bose-Einstein condensation in strongly coupled quark matter
• Number of the QCD critical points with neutral color superconductivity
• The axial anomaly and the phases of dense QCD

Cited by in corpus (6)

• Tachyonic instability of the scalar mode prior to QCD critical point based on Functional renormalization-group method
• Roles of axial anomaly on neutral quark matter with color superconducting phase
• BCS-BEC Crossover and Stability in a Nambu-Jona-Lasinio Model with Diquark-Diquark Repulsion
• Emergence of soft quark excitations by the coupling with a soft mode of the QCD critical point
• Generalized Fierz Identities and Applications to Spin-3/2 Particles
• Finite-size effects on the phase transition in a four- and six-fermion interaction model