Pathways to Real Composite Operators from Non-Hermitian Fermions

Abstract

A field theory in $3+1$ dimensions contains two fermions, two Abelian gauge fields, and one complex scalar, with dynamics fixed by a BRST symmetry. For a specific parameter configuration, the fermion mass matrix becomes non-Hermitian, and the propagators exhibit complex conjugate poles. We evaluate the one-loop fermion contribution to the two-point function of the composite operator $ϕ^{\dagger}ϕ$. Once the factor $i$ of the $e^{iS}$ normalization is removed, the contribution is real for real external momentum, which follows from the pairing of complex conjugate terms in the loop integral. The BRST construction of the action sets up a proof of renormalizability.