NNLO hard functions in massless QCD

TL;DR

This paper derives NNLO hard functions for all 2->2 processes in massless QCD, providing essential ingredients for precise higher-order resummations in collider physics.

Contribution

It presents analytic expressions for NNLO hard functions in massless QCD for all 2->2 processes, advancing the precision of theoretical predictions.

Findings

Analytic NNLO hard functions derived for all 2->2 massless QCD processes.

Hard functions are matrices in color space, finite after subtraction.

Facilitates higher-order resummation in collider phenomenology.

Abstract

We derive the hard functions for all 2->2 processes in massless QCD up to next-to-next-to-leading order (NNLO) in the strong coupling constant. By employing the known one- and two-loop helicity amplitudes for these processes, we obtain analytic expressions for the ultraviolet and infrared finite, minimally subtracted hard functions, which are matrices in color space. These hard functions will be useful in carrying out higher-order resummations in processes such as dijet and highly energetic top-quark pair production by means of soft-collinear effective theory methods.