The colourful antenna subtraction method

Abstract

We present a general subtraction scheme for NNLO calculations in massless QCD: the \textit{colourful antenna subtraction method}. It is a reformulation of the antenna subtraction approach designed to address some of the limitations of the traditional framework, especially aiming at high-multiplicity processes. In the context of the new formalism, structures needed to locally subtract the infrared-divergent behaviour of real emission corrections are systematically inferred from virtual subtraction terms, relying on the cancellation of infrared singularities and on the correspondence between integrated and unintegrated antenna functions. We illustrate in detail how the colourful antenna subtraction method works up to NNLO. The algorithm is particularly suited to be fully automated for the generation of NNLO subtraction terms for generic processes. We employ the new formalism to assemble the subtraction terms required for the calculation of the NNLO correction to hadronic three-jet production and describe their validation procedure