On a renormalizable class of gauge fixings for the gauge invariant operator A2min

Abstract

The dimension-two gauge-invariant nonlocal operator A2min, obtained through the minimization of the integral of A^2 along the gauge orbit, allows the introduction of a nonlocal gauge-invariant configuration Ah_mu, which can be employed to build a class of Euclidean massive Yang-Mills models useful to investigate nonperturbative infrared effects of confining theories. A fully local setup for both A2min and Ah_mu can be achieved, resulting in a local and BRST-invariant action which shares similarities with the Stueckelberg formalism. However, unlike the Stueckelberg action, the use of A2min gives rise to an all-orders renormalizable action. This feature is illustrated by means of a class of covariant gauge fixings which, similarly to the ’t Hooft R_zeta gauge of spontaneously broken gauge theories, provide a mass for the Stueckelberg field.