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Related papers: NLO cross sections in 4 dimensions without DREG

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We propose a new method to calculate the 4-dimensional divergent integrals. By calculating the one loop integral as an example, the regularization of the integrals in 3-dimension momentum space are given in details. We find that the new…

High Energy Physics - Theory · Physics 2007-05-23 Liang-gang Liu , Xiang-Qian Luo , Wei Chen

We compute the one-loop QCD amplitude for the process gg-->Q\bar{Q} in dimensional regularization through order \epsilon^2 in the dimensional regulator and for arbitrary quark mass values. This result is an ingredient of the NNLO…

High Energy Physics - Phenomenology · Physics 2008-12-30 Charalampos Anastasiou , S. Mert Aybat

We study the next-to-next-to-leading order (NNLO) evolution of flavour non-singlet quark densities and structure functions in massless perturbative QCD. Present information on the corresponding three-loop splitting functions is used to…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. L. van Neerven , A. Vogt

We calculate the four-loop massless QCD corrections with three closed quark lines to quark and gluon form factors. We apply a novel integration by parts algorithm based on modular arithmetic and compute all relevant master integrals for…

High Energy Physics - Phenomenology · Physics 2017-03-01 Andreas von Manteuffel , Robert M. Schabinger

The inclusive four-particle phase space integral of any $1\to 4$ matrix element in massless QCD contains divergences due to the soft and collinear emission of up to two particles in the final state. We show that any term appearing in this…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Gehrmann-De Ridder , T. Gehrmann , G. Heinrich

Heading towards a full automation of next-to-leading order (NLO) QCD corrections, one important ingredient is the analytical integration over the one-particle phase space of the unresolved particle that is necessary when adding the…

High Energy Physics - Phenomenology · Physics 2015-03-14 Rikkert Frederix , Thomas Gehrmann , Nicolas Greiner

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

In this talk we discuss an algorithm for the numerical calculation of one-loop QCD amplitudes and present results at next-to-leading order for jet observables in electron-positron annihilation calculated with the above-mentioned method. The…

High Energy Physics - Phenomenology · Physics 2011-12-16 S. Becker , D. Goetz , C. Reuschle , C. Schwan , S. Weinzierl

We consider Next-to-Leading-Order QCD corrections to ADD graviton exchange relevant for Deep Inelastic Scattering experiments. We calculate the relevant NLO structure functions by calculating the virtual and real corrections for a set of…

High Energy Physics - Phenomenology · Physics 2011-06-21 W. J. Stirling , E. Vryonidou

We present the computational framework MATRIX which allows us to evaluate fully differential cross sections for a wide class of processes at hadron colliders in next-to-next-to-leading order (NNLO) QCD. The processes we consider are $2\to…

High Energy Physics - Phenomenology · Physics 2018-08-01 Massimiliano Grazzini , Stefan Kallweit , Marius Wiesemann

We compute next-to-leading order (NLO) perturbative QCD corrections to the correlators of interpolating pentaquark currents. We employ modular techniques in configuration space which saves us from the onus of having to do loop calculations.…

High Energy Physics - Phenomenology · Physics 2012-08-28 S. Groote , J. G. Körner , A. A. Pivovarov

We present the first results for the ${\cal O}(\alpha\alpha_s)$ corrections to the total partonic cross section of the process $q\bar q\to Z+X$, with the complete set of contributions, that include photonic and massive weak gauge boson…

High Energy Physics - Phenomenology · Physics 2020-03-04 Roberto Bonciani , Federico Buccioni , Narayan Rana , Ilario Triscari , Alessandro Vicini

We discuss the contribution coming from the infrared region to NLO matrix elements and/or coefficient functions of hard QCD processes. Strictly speaking, this contribution is not known theoretically, since it is beyond perturbative QCD. For…

High Energy Physics - Phenomenology · Physics 2015-06-05 E. G. de Oliveira , A. D. Martin , M. G. Ryskin

We briefly review a subtraction scheme for computing radiative corrections to QCD jet cross sections that can be defined at any order in perturbation theory. Hereafter we discuss the computational methods used to evaluate analytically and…

High Energy Physics - Phenomenology · Physics 2011-04-20 Paolo Bolzoni , Gabor Somogyi

In order to calculate cross sections with a large number of particles/jets in the final state at next-to-leading order, one has to reduce the occurring scalar and tensor one-loop integrals to a small set of known integrals. In massless…

High Energy Physics - Phenomenology · Physics 2009-10-31 G. Heinrich , T. Binoth

One of the main difficulties in studying Quantum Field Theory, in the perturbative regime, is the calculation of D-dimensional Feynman integrals. In general, one introduces the so-called Feynman parameters and associated with them the…

High Energy Physics - Theory · Physics 2008-11-26 A. T. Suzuki , A. G. M. Schmidt

We present a new formulation of the loop-tree duality theorem for higher loop diagrams valid both for massless and massive cases. $l$-loop integrals are expressed as weighted sum of trees obtained from cutting $l$ internal propagators of…

High Energy Physics - Phenomenology · Physics 2019-11-22 Robert Runkel , Zoltán Szőr , Juan Pablo Vesga , Stefan Weinzierl

We construct a specific formalism for calculating the one-loop virtual corrections for standard model processes with an arbitrary number of external legs. The procedure explicitly separates the infrared and ultraviolet divergences…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. T. Giele , E. W. N. Glover

We compute the polarized splitting functions in the triple collinear limit at next-to-leading order accuracy (NLO) in the strong coupling $\alpha_{\rm S}$, for the splitting processes $\gamma \to q \bar{q} \gamma$, $\gamma \to q \bar{q} g$…

High Energy Physics - Phenomenology · Physics 2015-03-12 German F. R. Sborlini , Daniel de Florian , German Rodrigo

In the context of a subtraction method for jet cross sections at NNLO accuracy in the strong coupling, we perform the integration over the two-particle factorised phase space of the collinear-type contributions to the doubly unresolved…

High Energy Physics - Phenomenology · Physics 2015-06-12 Vittorio Del Duca , Gabor Somogyi , Zoltan Trocsanyi