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Scattering amplitudes of partons in QCD contain infrared divergences which can be resummed to all orders in terms of an anomalous dimension. Independently, in the limit of high-energy forward scattering, large logarithms of the energy can…

High Energy Physics - Phenomenology · Physics 2020-05-20 Simon Caron-Huot , Einan Gardi , Joscha Reichel , Leonardo Vernazza

We present the NNLO QCD virtual corrections for qurak-antiquark -> gluon photon, quark-antiquark -> photon photon and the NNLO QED virtual corrections for electron positron -> photon photon and all processes related by crossing symmetry. We…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. Anastasiou , E. W. N. Glover , M. E. Tejeda-Yeomans

The soft anomalous dimension governs the infrared singularities of scattering amplitudes to all orders in perturbative quantum field theory, and is a crucial ingredient in both formal and phenomenological applications of non-abelian gauge…

High Energy Physics - Phenomenology · Physics 2017-10-25 Øyvind Almelid , Claude Duhr , Einan Gardi , Andrew McLeod , Chris D. White

We combine the observable-based formalism (KMOC), the analytic properties of the scattering amplitude, generalised unitarity and the heavy-mass expansion with a newly introduced IBP reduction for Fourier integrals, to provide an efficient…

High Energy Physics - Theory · Physics 2024-12-17 Giacomo Brunello , Stefano De Angelis

We report on the recent completion of the three-loop calculation of the soft anomalous dimension in massless gauge-theory scattering amplitudes. This brings the state-of-the-art knowledge of long-distance singularities in multi-leg QCD…

High Energy Physics - Phenomenology · Physics 2016-06-21 Einan Gardi , Øyvind Almelid , Claude Duhr

Future high luminosity polarized deep--inelastic scattering experiments will improve both the knowledge of the spin sub--structure of the nucleons and contribute further to the precision determination of the strong coupling constant, as…

High Energy Physics - Phenomenology · Physics 2022-02-16 J. Blümlein , P. Marquard , C. Schneider , K. Schönwald

Generalised bi-adjoint scalar amplitudes, obtained from integrations over moduli space of punctured $\mathbb{CP}^{k-1}$, are novel extensions of the CHY formalism. These amplitudes have realisations in terms of Grassmannian cluster…

High Energy Physics - Theory · Physics 2021-05-19 Md. Abhishek , Subramanya Hegde , Arnab Priya Saha

We present the analytic form of all leading-color two-loop five-parton helicity amplitudes in QCD. The results are analytically reconstructed from exact numerical evaluations over finite fields. Combining a judicious choice of variables…

High Energy Physics - Phenomenology · Physics 2019-05-23 S. Abreu , J. Dormans , F. Febres Cordero , H. Ita , B. Page , V. Sotnikov

I discuss the state-of-the-art knowledge of long-distance singularities in multi-leg gauge-theory scattering amplitudes and report on an on-going calculation of the three-loop soft anomalous dimension through the renormalization of…

High Energy Physics - Phenomenology · Physics 2014-07-22 Einan Gardi

We compute the leading-color (planar) three-loop four-point amplitude of N=4 supersymmetric Yang-Mills theory in 4 - 2 epsilon dimensions, as a Laurent expansion about epsilon = 0 including the finite terms. The amplitude was constructed…

High Energy Physics - Theory · Physics 2008-11-26 Zvi Bern , Lance J. Dixon , Vladimir A. Smirnov

Multiloop scattering amplitudes describing the quantum fluctuations at high-energy scattering processes are the main bottleneck in perturbative quantum field theory. The loop-tree duality is a novel method aimed at overcoming this…

We compute all master integrals for massless three-loop four-particle scattering amplitudes required for processes like di-jet or di-photon production at the LHC. We present our result in terms of a Laurent expansion of the integrals in the…

High Energy Physics - Phenomenology · Physics 2020-05-20 Johannes Henn , Bernhard Mistlberger , Vladimir A. Smirnov , Pascal Wasser

Scattering amplitudes in the high-energy limit can be described in terms of their singularity structure in the complex angular momentum plane, consisting of Regge poles and cuts. In QCD, gluon Reggeization has long been understood as a…

High Energy Physics - Phenomenology · Physics 2024-12-31 Samuel Abreu , Giulio Falcioni , Einan Gardi , Calum Milloy , Leonardo Vernazza

We carry out a systematic investigation of all the 2-loop integrals occurring in the electron vertex in QED in the continuous $D$-dimensional regularization scheme, for on-shell electrons, momentum transfer $t=-Q^2$ and finite squared…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Bonciani , P. Mastrolia , E. Remiddi

We derive an ABDK-like relation between the one- and two-loop four-graviton amplitudes in N=8 supergravity. Specifically we show that the infrared divergent part of the two-loop amplitude is one-half the square of the one-loop amplitude,…

High Energy Physics - Theory · Physics 2008-11-26 Stephen G. Naculich , Horatiu Nastase , Howard J. Schnitzer

We discuss possibilities of measurement of deeply virtual Compton scattering amplitudes via different asymmetries in order to access the underlying skewed parton distributions. Perturbative one-loop coefficient functions and two-loop…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. V. Belitsky , D. Müller , L. Niedermeier , A. Schäfer

We show that the evaluation of scattering amplitudes can be formulated as a problem of multivariate polynomial division, with the components of the integration-momenta as indeterminates. We present a recurrence relation which, independently…

High Energy Physics - Phenomenology · Physics 2015-06-05 Pierpaolo Mastrolia , Edoardo Mirabella , Giovanni Ossola , Tiziano Peraro

We present a simplified variant of the integrand reduction algorithm for multiloop scattering amplitudes in $d = 4 - 2\epsilon$ dimensions, which exploits the decomposition of the integration momenta in parallel and orthogonal subspaces,…

High Energy Physics - Phenomenology · Physics 2016-07-19 Pierpaolo Mastrolia , Tiziano Peraro , Amedeo Primo , William J. Torres Bobadilla

We derive the full system of canonical differential equations for all planar two-loop massless six-particle master integrals, and determine analytically the boundary conditions. This fully specifies the solutions, which may be written as…

High Energy Physics - Phenomenology · Physics 2025-01-20 Johannes Henn , Antonela Matijašić , Julian Miczajka , Tiziano Peraro , Yingxuan Xu , Yang Zhang

Two-quark--two-antiquark systems with four different quark flavors are considered in the framework of two-dimensional QCD, in the light-cone gauge, at leading orders of the $1/N_c^{}$ expansion. Introducing basis functions with…

High Energy Physics - Phenomenology · Physics 2025-09-22 Hagop Sazdjian