Some Nonrenormalization Theorems in Curci–ferrari Model

In the present paper, a particular form of Slavnov–Taylor identities for the Curci–Ferrari model is deduced. This model consist of Yang–Mills theory in a particular nonlinear covariant gauge, supplemented with mass terms for gluons and ghosts. It can be used as a regularization for the Yang–Mills theory preserving simple Slavnov–Taylor identities. Employing these identities, two nonrenormalization theorems are proved that reduce the number of independent renormalization factors from five to three. These new relations are verified by a comparison to the already known three-loops renormalization factors. These relations include, as a particular case, the corresponding known identities in Yang–Mills theory in Landau gauge.