Chiral symmetry breaking and monopole dynamics in non-compact QED3 coupled to a four-fermi interaction

TL;DR

This paper presents pioneering lattice simulations of non-compact QED3 with four fermion flavors and a four-fermi interaction, revealing the nature of the chiral transition and monopole behavior.

Contribution

It provides the first lattice results on QED3 with four fermion flavors coupled to a four-fermi interaction, analyzing critical behavior and monopole effects.

Findings

Scaling near the chiral transition is governed by the 3d Gross Neveu fixed point.

Small deviations suggest gauge field dynamics may generate fermion mass.

Monopoles are shielded and do not influence confinement at weak couplings.

Abstract

We present results from the first lattice simulations of three dimensional non-compact quantum electrodynamics (QED3) with N_f four-component fermion flavors coupled to a weak Z(2) chirally invariant four-fermi interaction. Results with $N_f \ge 4$ show that the scaling near the strong coupling chiral transition or sharp crossover is determined by the 3d Gross Neveu ultraviolet-stable renormalization group fixed point. Small deviations of the N_f=4 critical exponents from the respective Gross Neveu ones, hint at evidence for non-zero fermion mass generated by the gauge fields dynamics that might have been enhanced by the four-fermi coupling. It is also shown that the scaling region is suppressed at weak four-fermi couplings and large N_f values. Measurements of i) a monopole susceptibility which is the polarizability of the monopole configurations, and ii) the density of isolated monopoles, imply that for $N_f \ge 1$ and weak gauge couplings the monopoles do not affect the theory's confining properties, because they are shielded.