Recently, we have presented the result for the zero-jettiness soft function at next-to-next-to-next-to-leading order (N3LO) in perturbative QCD [arXiv:2409.11042], without providing technical details of the calculation. The goal of this paper is to describe the most important element of that computation, the triple real-emission contribution. We present a detailed discussion of the many technical aspects of the calculation, for which a number of methodological innovations was required. Although some elements of the calculation were discussed earlier [arXiv:2004.03285,arXiv:2206.12323,arXiv:2111.13594,arXiv:2204.09459,arXiv:2401.05245], this paper is intended to provide a complete summary of the methods used in the computation of the triple real-emission contribution to the soft function.
@article{arxiv.2412.14001,
title = {Triple real-emission contribution to the zero-jettiness soft function at N3LO in QCD},
author = {Daniel Baranowski and Maximilian Delto and Kirill Melnikov and Andrey Pikelner and Chen-Yu Wang},
journal= {arXiv preprint arXiv:2412.14001},
year = {2024}
}