The (2+1)-dimensional Gross–Neveu model with a U(1) chiral symmetry at nonzero temperature

• Published in: Physics letters. B Vol. 515; no. 3-4; pp. 407 - 413
• Main Authors: Hands, S.J., Kogut, J.B., Strouthos, C.G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30-08-2001
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/S0370-2693(01)00885-1

We present results from numerical simulations of the (2+1)-dimensional Gross–Neveu model with a U(1) chiral symmetry and Nf=4 fermion species at nonzero temperature. We provide evidence that there are two different chirally symmetric phases, one critical and one with finite correlation length, separated by a Berezinskii–Kosterlitz–Thouless transition. We have also identified a regime above the critical temperature in which the fermions acquire a screening mass even in the absence of chiral symmetry breaking, analogous to the pseudogap behaviour observed in cuprate superconductors.