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Related papers: A new method for calculating the soft anomalous di…

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The soft anomalous dimension governs the infrared divergences of scattering amplitudes in general kinematics to all orders in perturbation theory. By comparing the recent Regge-limit results for $2\to2$ scattering (through…

High Energy Physics - Phenomenology · Physics 2022-02-07 Niamh Maher , Giulio Falcioni , Einan Gardi , Calum Milloy , Leonardo Vernazza

Feynman amplitudes at higher orders in perturbation theory generically have complex singular structures. Notwithstanding the emergence of many powerful new methods, the presence of infrared divergences poses significant challenges for their…

High Energy Physics - Phenomenology · Physics 2019-09-04 Charalampos Anastasiou , George Sterman

We revisit the multi-loop structure of the anomalous-dimension matrix governing the infrared divergences of massless $n$-particle scattering amplitudes in non-abelian gauge theories. In particular, we derive its most general form at…

High Energy Physics - Phenomenology · Physics 2020-01-29 Thomas Becher , Matthias Neubert

Wilson lines capture important features of scattering amplitudes, for example soft effects relevant for infrared divergences, and the Regge limit. Beyond the leading power approximation, corrections to the eikonal picture have to be taken…

High Energy Physics - Theory · Physics 2018-05-23 Robin Brüser , Simon Caron-Huot , Johannes M. Henn

Scattering amplitudes are expected to admit a factorised structure in special kinematic limits, such as the Regge, soft and collinear limits. However, less is known about the precise mechanisms through which factorisation of $n$-particle…

High Energy Physics - Phenomenology · Physics 2025-07-30 Claude Duhr , Einan Gardi , Sebastian Jaskiewicz , Jonas Lübken , Leonardo Vernazza

In this paper we develop further and refine the method of differential equations for computing Feynman integrals. In particular, we show that an additional iterative structure emerges for finite loop integrals. As a concrete non-trivial…

High Energy Physics - Theory · Physics 2015-06-19 Simon Caron-Huot , Johannes M. Henn

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions, which has been computed through two loops. The two-loop matrix is proportional to the one-loop matrix. Recently there have been…

High Energy Physics - Phenomenology · Physics 2009-10-29 Lance J. Dixon

We present the computation of a full set of planar five-point two-loop master integrals with one external mass. These integrals are an important ingredient for two-loop scattering amplitudes for two-jet-associated W-boson production at…

High Energy Physics - Phenomenology · Physics 2020-12-30 S. Abreu , H. Ita , F. Moriello , B. Page , W. Tschernow , M. Zeng

Within the framework proposed by Caron-Huot and Wilhelm, we give a recipe for computing infrared anomalous dimensions purely on-shell, efficiently up to two loops in any massless theory. After introducing the general formalism and reviewing…

High Energy Physics - Theory · Physics 2023-05-29 Pietro Baratella , Sara Maggio , Michael Stadlbauer , Tobias Theil

Scattering amplitudes at loop level can be expressed in terms of Feynman integrals. The latter satisfy partial differential equations in the kinematical variables. We argue that a good choice of basis for (multi-)loop integrals can lead to…

High Energy Physics - Theory · Physics 2013-06-26 Johannes M. Henn

We present compact integral representations for the calculation of two-loop anomalous dimensions for a generic class of soft functions that are defined in terms of two light-like Wilson lines. Our results are relevant for the resummation of…

High Energy Physics - Phenomenology · Physics 2019-03-28 Guido Bell , Rudi Rahn , Jim Talbert

A formula for the two-loop infrared singularities of dimensionally regularized QCD scattering amplitudes with an arbitrary number of massive and massless legs is derived. The singularities are obtained from the solution of a…

High Energy Physics - Phenomenology · Physics 2014-11-18 Thomas Becher , Matthias Neubert

The infrared divergences of QCD scattering amplitudes can be derived from an anomalous dimension \Gamma, which is a matrix in color space and depends on the momenta and masses of the external partons. It has recently been shown that in…

High Energy Physics - Phenomenology · Physics 2009-11-19 Andrea Ferroglia , Matthias Neubert , Ben D. Pecjak , Li Lin Yang

We report on further progress in understanding soft singularities of massless gauge theory scattering amplitudes. Recently, a set of equations was derived based on Sudakov factorization, constraining the soft anomalous dimension matrix of…

High Energy Physics - Phenomenology · Physics 2011-08-17 Lance J. Dixon , Einan Gardi , Lorenzo Magnea

Infrared divergences in Quantum Field Theory govern the low-energy dynamics of many physical theories, and their understanding is a crucial ingredient in predicting the outcomes of collider experiments. We present a novel approach to…

High Energy Physics - Theory · Physics 2025-06-19 Carolina Figueiredo , Giulio Gambuti , Holmfridur S. Hannesdottir

We extend the resummation of dimensionally-regulated amplitudes to next-to-next-to-leading poles. This requires the calculation of two-loop anomalous dimension matrices for color mixing through soft gluon exchange. Remarkably, we find that…

High Energy Physics - Phenomenology · Physics 2009-04-06 S. Mert Aybat , Lance J. Dixon , George Sterman

We establish a systematic way to calculate multiloop amplitudes of infrared safe massless models with Implicit Regularization (IR), with a direct cancelation of the fictitious mass introduced by the procedure. The ultraviolet content of…

High Energy Physics - Theory · Physics 2015-05-14 E. W. Dias , A. P. Baeta Scarpelli , L. C. T. Brito , H. G. Fargnoli

The cross or soft anomalous dimension matrix describes the renormalization of Wilson loops with a self-intersection and is an important object in the study of infrared divergences of scattering amplitudes. In this paper it is studied for…

High Energy Physics - Theory · Physics 2020-03-12 Hagen Münkler

We establish a correspondence between ultraviolet singularities of soft factors for multiparticle production and rapidity singularities of soft factors for multiparton scattering. This correspondence is a consequence of the conformal…

High Energy Physics - Phenomenology · Physics 2017-02-24 Alexey A. Vladimirov

Scattering amplitudes involving multiple partons are plagued with infrared singularities. The soft singularities of the amplitude are captured by the soft function which is defined as the vacuum expectation value of Wilson line correlators.…

High Energy Physics - Phenomenology · Physics 2024-07-02 Shubham Mishra , Sourav Pal , Aditya Srivastav , Anurag Tripathi