Correlator webs of massive multiparton amplitudes at four loops: A study of boomerang webs

TL;DR

This paper advances the understanding of four-loop multiparton amplitudes by providing complete mixing matrices and color factors for boomerang webs, introducing an improved algorithm for generating these complex diagrams.

Contribution

It offers the first complete mixing matrices and exponentiated color factors for four-loop boomerang webs connecting multiple Wilson lines, and introduces a more efficient Cweb generation algorithm.

Findings

Complete mixing matrices for four-loop boomerang webs

Exponentiated color factors for these webs

An improved algorithm for Cweb generation

Abstract

Logarithm of the soft function can be organized into sets of Feynman diagrams known as Cwebs. We introduced a new formalism in~\cite{Agarwal:2022wyk}, that allows to determine several of the building blocks of Cweb mixing matrices without explicit computations. In~\cite{Agarwal:2022xec} we used this formalism to obtain the diagonal blocks of four general classes of Cwebs to all orders in perturbation theory which also covered all the four loop Boomerang Cwebs connecting four Wilson lines. In this work we present complete mixing matrices and exponentiated colour factors for Boomerang Cwebs at four loops that connect three and four Wilson lines. Also, we present a more efficient version of the algorithm of generating Cwebs that was presented in~\cite{Agarwal:2020nyc}. This new algorithm has been used to generate the Cwebs in the present work.