Influence of strong magnetic fields and instantons on the phase structure of the two-flavor Nambu-Jona-Lasinio model

Journal Article · Thu Apr 01 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.074005· OSTI ID:21409468

Boomsma, Jorn K; Boer, Danieel ^[1]

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1. Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, NL-1081 HV Amsterdam (Netherlands)

Both in heavy-ion collisions and in magnetars very strong magnetic fields are produced, which has an influence on the phases of matter involved. In this paper we investigate the effect of strong magnetic fields (B{approx}5m{sub {pi}}{sup 2}/e=1.7x10{sup 19} G) on the chiral symmetry restoring phase transition using the Nambu-Jona-Lasinio model. It is observed that the pattern of phase transitions depends on the relative magnitude of the magnetic field and the instanton interaction strength. We study two specific regimes in the phase diagram, high chemical potential and zero temperature and vice versa, which are of relevance for neutron stars and heavy-ion collisions, respectively. In order to shed light on the behavior of the phase transitions, we study the dependence of the minima of the effective potential on the occupation of Landau levels. We observe a near degeneracy of multiple minima with differing occupation numbers, of which some become the global minimum upon changing the magnetic field or the chemical potential. These minima differ considerably in the amount of chiral symmetry breaking and, in some cases, also of isospin breaking.

• OSTI ID: 21409468
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 7; Other Information: DOI: 10.1103/PhysRevD.81.074005; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRAL SYMMETRY
FLAVOR MODEL
HEAVY ION REACTIONS
INTERACTIONS
ISOSPIN
MAGNETIC FIELDS
NEUTRON STARS
OCCUPATIONS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SIMULATION
SYMMETRY BREAKING
COMPOSITE MODELS
DIAGRAMS
INFORMATION
MATHEMATICAL MODELS
NUCLEAR REACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
QUARK MODEL
STARS
SYMMETRY