MT: a Mathematica package to compute convolutions
Maik Hoeschele, Jens Hoff, Alexey Pak, Matthias Steinhauser, Takahiro Ueda
TL;DR
Problem addressed: collinear divergences in initial-state radiation require convolutions of partonic cross sections with splitting functions. Approach: MT implements a Mellin-space algorithm using regularized derivatives to handle harmonic polylogarithms (HPLs), plus distributions, and polynomials, enabling analytic and numeric convolutions up to weight eight. Key contributions: a comprehensive Mathematica package MT with Mellin-transform pipelines and utilities for HPLs and harmonic sums, plus explicit demonstrations for Higgs production and Drell–Yan up to N^3LO, including new Drell–Yan results and ε-expansion terms. Significance: provides a practical tool for NNLO/N^3LO phenomenology and downloadable data/resources for collaborations.
Abstract
We introduce the \prog{Mathematica} package \prog{MT} which can be used to compute, both analytically and numerically, convolutions involving harmonic polylogarithms, polynomials or generalized functions. As applications contributions to next-to-next-to-next-to leading order Higgs boson production and the Drell-Yan process are discussed.
