Nonlinear sigma model approach for chiral fluctuations and symmetry breakdown in the Nambu-Jona-Lasinio model
2000 (English)In: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 6207, no 7Article in journal (Refereed) Published
Tills paper is organized in two parts. We start with the observation that the recent claim that the chiral symmetry in the Nambu-Jona-Lasinio (NJL) model is necessarily restored by violent chiral fluctuations at N-c = 3 [H. Kleinert and B. Van den Bossche, Phys. Lett. B 474, 336 (2000)] appears to be incorrect since the critical stiffness of the effective nonlinear sigma model used in the above reference is not a universal quantity in 3 + 1 dimensions. In the second part we discuss a modified Nn model, where the critical stiffness is expressed via an additional cutoff parameter. This model displays a symmetry breakdown, and also under certain conditions the chiral fluctuations give rise to a phase analogous to pseudogap phase of superconductors with strong coupling or low carrier density.
Place, publisher, year, edition, pages
2000. Vol. 6207, no 7
bose-einstein condensation, strong-coupling superconductivity, ginzburg-landau-theory, bcs-superconductivity, finite-temperature, phase-transitions, coherence length, nuclear-matter, crossover, pseudogap
IdentifiersURN: urn:nbn:se:kth:diva-20084ISI: 000089749400049OAI: oai:DiVA.org:kth-20084DiVA: diva2:338777
QC 201005252010-08-102010-08-10Bibliographically approved