Feynman rules for the Rational Part of the Electroweak 1-loop amplitudes in the Rξ gauge and in the Unitary gauge

Abstract

We present the complete set of Feynman rules producing the rational terms of kind R2 needed to perform any 1-loop calculation in the Electroweak Standard Model. Our formulae are given both in the Rξ gauge and in the Unitary gauge, therefore completing the results in the 't Hooft-Feynman gauge already presented in a previous publication. As a consistency check, we verified, in the case of the process H → γγ and in a few other physical cases, the independence of the total Rational Part (R1 + R2) on the chosen gauge. In addition, we explicitly checked the equivalence of the limits ξ → ∞ after or before the loop momentum integration in the definition of the Unitary gauge at 1-loop. © SISSA 2011.