TY - JOUR

T1 - Directional dependence of a color superconducting gap in two-flavor QCD in a magnetic field

AU - Yu, Lang

AU - Shovkovy, Igor

N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.

PY - 2012/4/19

Y1 - 2012/4/19

N2 - We study the effect of a magnetic field on the pairing dynamics in two-flavor color superconducting dense quark matter. The study is performed in the weakly coupled regime of QCD at asymptotically high density, using the framework of the Schwinger-Dyson equation in the improved rainbow approximation. We show that the superconducting gap function develops a directional dependence in momentum space. Quasiparticles with momenta perpendicular to the direction of the magnetic field have the largest gaps, while quasiparticles with momenta parallel to the field have the smallest gaps. We argue that the directional dependence is a consequence of a long-range interaction in QCD. The quantitative measure of the ellipticity of the gap function is determined by a dimensionless ratio, proportional to the square of the magnetic field and inversely proportional to the fourth power of the quark chemical potential. For magnetic fields in stars, B 1018G, the corresponding ratio is estimated to be less than about 10 -2, justifying the use of the weak magnetic field limit in all stellar applications.

AB - We study the effect of a magnetic field on the pairing dynamics in two-flavor color superconducting dense quark matter. The study is performed in the weakly coupled regime of QCD at asymptotically high density, using the framework of the Schwinger-Dyson equation in the improved rainbow approximation. We show that the superconducting gap function develops a directional dependence in momentum space. Quasiparticles with momenta perpendicular to the direction of the magnetic field have the largest gaps, while quasiparticles with momenta parallel to the field have the smallest gaps. We argue that the directional dependence is a consequence of a long-range interaction in QCD. The quantitative measure of the ellipticity of the gap function is determined by a dimensionless ratio, proportional to the square of the magnetic field and inversely proportional to the fourth power of the quark chemical potential. For magnetic fields in stars, B 1018G, the corresponding ratio is estimated to be less than about 10 -2, justifying the use of the weak magnetic field limit in all stellar applications.

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U2 - 10.1103/PhysRevD.85.085022

DO - 10.1103/PhysRevD.85.085022

M3 - Article

AN - SCOPUS:84860134780

VL - 85

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

SN - 1550-7998

IS - 8

M1 - 085022

ER -