Nonlinear gauge fixing with auxiliary fields

Abstract

We study renormalizability of gauge theories in nonlinear gauges with the help of auxiliary fields. We show that the auxiliary-field formulation is particularly helpful in understanding the divergence structures in the nonlinear gauges. A quadratic gauge-fixing choice in non-Abelian gauge theory in general induces quartic ghost terms. We show that there can exist various Becchi-Rouet-Stora-invariant Lagrangians involving quartic ghosts. However, renormalizability only selects out the Lagrangian which respects the global invariance corresponding to the original gauge group.