Single-flavor CSL phase in compact stars

Journal Article · Fri Aug 29 00:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2987171· OSTI ID:21152391

Blaschke, David ^[1]; Sandin, Fredrik ^[2]; Klaehn, Thomas ^[3]; Berdermann, Jens ^[4]

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1. Instytut Fizyki Teoretycznej, Uniwersytet Wroclawski, 50-204 Wroclaw (Poland)
2. Departement d'Astrophysique, de Geophysique et d'Oceanographie, Universite de Liege, B5a, Sart-Tilman, B-4000 Liege (Belgium)
3. Theory Division, Argonne National Laboratory, Argonne IL (United States)
4. DESY Zeuthen, Platanenallee 6, D-15738 Berlin (Germany)

We suggest a scenario where the three light quark flavors are sequentially deconfined under increasing pressure in cold asymmetric nuclear matter as, e.g., in neutron stars. The basis for our analysis is a chiral quark matter model of Nambu-Jona-Lasinio (NJL) type with diquark pairing in the spin-1 single flavor (CSL), spin-0 two flavor (2SC) and three flavor (CFL) channels. We find that nucleon dissociation sets in at about the saturation density, n{sub 0}, when the down-quark Fermi sea is populated (d-quark dripline) due to the flavor asymmetry induced by {beta}-equilibrium and charge neutrality. At about 3n{sub 0} u-quarks appear and a two-flavor color superconducting (2SC) phase is formed. The s-quark Fermi sea is populated only at still higher baryon density, when the quark chemical potential is of the order of the dynamically generated strange quark mass. We construct two different hybrid equations of state (EoS) using the Dirac-Brueckner Hartree-Fock (DBHF) approach and the EoS by Shen et al. in the nuclear matter sector. The corresponding hybrid star sequences have maximum masses of, respectively, 2.1 and 2.0 M{sub {center_dot}}. Two- and three-flavor quark-matter phases exist only in gravitationally unstable hybrid star solutions in the DBHF case, while the Shen-based EoS produce stable configurations with a 2SC phase component in the core of massive stars. Nucleon dissociation due to d-quark drip at the crust-core boundary fulfills basic criteria for a deep crustal heating process which is required to explain superbusts as well as cooling of X-ray transients.

• OSTI ID: 21152391
• Journal Information: AIP Conference Proceedings, Vol. 1038, Issue 1; Conference: HLPW 2008: Joint meeting Heidelberg-Liege-Paris-Wroclaw on hadronic physics, Spa (Belgium), 6-8 Mar 2008; Other Information: DOI: 10.1063/1.2987171; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
CHIRAL SYMMETRY
CHIRALITY
COLOR MODEL
D QUARKS
EQUATIONS OF STATE
FLAVOR MODEL
HARTREE-FOCK METHOD
MATHEMATICAL SOLUTIONS
NEUTRON STARS
NUCLEAR MATTER
NUCLEONS
POTENTIALS
QUANTUM CHROMODYNAMICS
QUARK MATTER
S QUARKS
SPIN
SYMMETRY BREAKING
TRANSIENTS
U QUARKS