Next-to-leading power two-loop soft functions for the Drell-Yan process at threshold

Autor: Alessandro Broggio, Sebastian Jaskiewicz, Leonardo Vernazza
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Journal of High Energy Physics, Vol 2021, Iss 10, Pp 1-31 (2021)
Druh dokumentu: article
ISSN: 1029-8479
DOI: 10.1007/JHEP10(2021)061
Popis: Abstract We calculate the generalized soft functions at O $$ \mathcal{O} $$ ( α s 2 $$ {\alpha}_s^2 $$ ) at next-to-leading power accuracy for the Drell-Yan process at threshold. The operator definitions of these objects contain explicit insertions of soft gauge and matter fields, giving rise to a dependence on additional convolution variables with respect to the leading power result. These soft functions constitute the last missing ingredient for the validation of the bare factorization theorem to NNLO accuracy. We carry out the calculations by reducing the soft squared amplitudes into a set of canonical master integrals and we employ the method of differential equations to evaluate them. We retain the exact d-dimensional dependence of the convolution variables at the integration boundaries in order to regulate the fixed-order convolution integrals. After combining the soft functions with the relevant collinear functions, we perform checks of the results at the cross-section level against the literature and expansion-by-regions calculations, at NNLO and partly at N3LO, finding agreement.
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