Massive fermions without fermion bilinear condensates

Abstract

We study a lattice field theory model containing two flavors of massless staggered fermions with an onsite four-fermion interaction. The model contains a $SU(4)$ symmetry which forbids non-zero fermion bilinear mass terms, due to which there is a massless fermion phase at weak couplings. However, even at strong couplings fermion bilinear condensates do not appear in our model, although fermions do become massive. While the existence of this exotic strongly coupled massive fermion phase was established long ago, the nature of the transition between the massless and the massive phase has remained unclear. Using Monte Carlo calculations in three space-time dimensions, we find evidence for a direct second order transition between the two phases suggesting that the exotic lattice phase may have a continuum limit at least in three dimensions. A similar exotic second order critical point was found recently in a bilayer system on a honeycomb lattice.

(17 pages, 7 figures, 9 tables)

References in corpus (5)

• Diagrammatic Monte Carlo simulation of non-equilibrium systems
• Restoration of chiral and $U(1{)}_A$ symmetries in excited hadrons
• Diagrammatic Determinantal methods: projective schemes and applications to the Hubbard-Holstein model
• The phase structure of a chirally invariant lattice Higgs-Yukawa model - numerical simulations
• Renormalization-Group Flows and Fixed Points in Yukawa Theories

Cited by in corpus (4)

• Generating a non-perturbative mass gap using Feynman diagrams in an asymptotically free theory
• Fermion Bag Approach for Hamiltonian Lattice Field Theories
• Fermion Bags and A New Origin for a Fermion Mass
• Fermion mass generation without a condensate