Effect of Strong Magnetic Field on Competing Order Parameters in Two-Flavor Dense Quark Matter

• Published in: Advances in High Energy Physics Vol. 2017; no. 2017; pp. 1 - 11
• Main Authors: Mandal, Tanumoy, Jaikumar, Prashanth
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 01.01.2017; Hindawi; John Wiley & Sons, Inc; Wiley
• Subjects: Analysis; Gravitational waves; Magnetic fields; Neutron stars; Neutrons; Physics; Quarks; Superconductors
• ISSN: 1687-7357; 1687-7365; 1687-7365
• DOI: 10.1155/2017/6472909

We study the effect of strong magnetic field on competing chiral and diquark order parameters in a regime of moderately dense quark matter. The interdependence of the chiral and diquark condensates through nonperturbative quark mass and strong coupling effects is analyzed in a two-flavor Nambu-Jona-Lasinio (NJL) model. In the weak magnetic field limit, our results agree qualitatively with earlier zero-field studies in the literature that find a critical coupling ratio G D / G S ~ 1.1 below which chiral or superconducting order parameters appear almost exclusively. Above the critical ratio, there exists a significant mixed broken phase region where both gaps are nonzero. However, a strong magnetic field B ≳ 1 0 18 G disrupts this mixed broken phase region and changes a smooth crossover found in the weak-field case to a first-order transition for both gaps at almost the same critical density. Our results suggest that in the two-flavor approximation to moderately dense quark matter strong magnetic field enhances the possibility of a mixed phase at high density, with implications for the structure, energetics, and vibrational spectrum of neutron stars.