Subtraction at NNLO
S. Frixione, M. Grazzini
TL;DR
The paper addresses the challenge of achieving NNLO precision in QCD by proposing an observable- and process-independent subtraction framework to cancel infrared singularities. It builds on universal subtraction concepts and introduces a general ENLO-based prescription for constructing and integrating subtraction counterterms, with a clear path from NLO to NNLO through a structured treatment of soft and collinear limits. The authors illustrate the approach on the CF T_R contribution to e+e- dijet production and develop phase-space measures to enable analytic integration of counterterms. This work lays groundwork for a complete NNLO subtraction formalism and potential future matching to parton showers, enhancing predictive power for collider phenomenology.
Abstract
We propose a framework for the implementation of a subtraction formalism at NNLO in QCD, based on an observable- and process-independent cancellation of infrared singularities. As a first simple application, we present the calculation of the contribution to the e+e- dijet cross section proportional to C_F T_R