Novel phases in strongly coupled four-fermion theories



Catterall, Simon and Schaich, David ORCID: 0000-0002-9826-2951
(2017) Novel phases in strongly coupled four-fermion theories. PHYSICAL REVIEW D, 96 (3). 034506-.

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Abstract

We study a lattice model comprising four massless reduced staggered fermions in four dimensions coupled through an $SU(4)$-invariant four-fermion interaction. We present both theoretical arguments and numerical evidence that no bilinear fermion condensates are present for any value of the four-fermi coupling, in contrast to earlier studies of Higgs--Yukawa models with different exact lattice symmetries. At strong coupling we observe the formation of a four-fermion condensate and a mass gap in spite of the absence of bilinear condensates. Unlike those previously studied systems we do not find a ferromagnetic phase separating this strong-coupling phase from the massless weak-coupling phase. Instead we observe long-range correlations in a narrow region of the coupling, still with vanishing bilinear condensates. While our numerical results come from relatively small lattice volumes that call for caution in drawing conclusions, if this novel phase structure is verified by future investigations employing larger volumes it may offer the possibility for new continuum limits for strongly interacting fermions in four dimensions.

Item Type: Article
Additional Information: 12 pages, 14 figures. Version to be published in PRD
Uncontrolled Keywords: hep-lat, hep-lat, cond-mat.str-el, hep-ph
Depositing User: Symplectic Admin
Date Deposited: 09 Mar 2020 09:06
Last Modified: 18 Jan 2023 23:58
DOI: 10.1103/PhysRevD.96.034506
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3078184