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Related papers: The Two-Loop QCD Matrix Element for $e^+e^- \to 3$…

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We establish an efficient polynomial-complexity algorithm for one-loop calculations, based on generalized $D$-dimensional unitarity. It allows automated computations of both cut-constructible {\it and} rational parts of one-loop scattering…

High Energy Physics - Phenomenology · Physics 2009-09-17 Walter T. Giele , Zoltan Kunszt , Kirill Melnikov

We report on recent progress for the QCD corrections to top quark pair plus jet production. In particular, we discuss a recent computation for the two-loop master integrals associated to a two-loop five-point pentagon-box integral…

High Energy Physics - Phenomenology · Physics 2023-10-17 Matteo Becchetti

We compute the two-loop corrections to the helicity amplitudes for the coupling of a massive vector boson to a massless quark-antiquark pair and a gluon, accounting for vector and axial-vector couplings of the vector boson and…

High Energy Physics - Phenomenology · Physics 2023-06-19 Thomas Gehrmann , Tiziano Peraro , Lorenzo Tancredi

With the increasing experimental precision available at colliders, higher-order perturbative calculations are required to reduce the theory uncertainty in order to extract crucial QCD parameters, such as the strong coupling constant, to the…

High Energy Physics - Phenomenology · Physics 2022-08-15 Marco Saragnese

In previous articles we outlined a subtraction scheme for regularizing doubly-real emission and real-virtual emission in next-to-next-to-leading order (NNLO) calculations of jet cross sections in electron-positron annihilation. In order to…

High Energy Physics - Phenomenology · Physics 2008-12-30 Gábor Somogyi , Zoltán Trócsányi

We present the analytic calculation of the two-loop QCD corrections to the decay width of a Higgs boson into a photon and a $Z$ boson. The calculation is carried out using integration-by-parts identities for the reduction to master…

High Energy Physics - Phenomenology · Physics 2015-09-30 R. Bonciani , V. Del Duca , H. Frellesvig , J. M. Henn , F. Moriello , V. A. Smirnov

We calculate the two-loop QCD correction to the scalar quark contributions to the electroweak gauge-boson self-energies at zero momentum-transfer in the supersymmetric extension of the Standard Model. We then derive the $O(\alpha_s)$…

High Energy Physics - Phenomenology · Physics 2009-07-09 A. Djouadi , P. Gambino , S. Heinemeyer , W. Hollik , C. Jünger , G. Weiglein

Heavy--light QCD currents are matched with HQET currents at two loops and leading order in $1/m$. A single formula applies to all current matchings. As a by--product, a master formula for the two--loop anomalous dimension of the QCD current…

High Energy Physics - Phenomenology · Physics 2009-10-28 D. J. Broadhurst , A. G. Grozin

The NNLO QCD corrections to the $e^+e^- \to 3$ jets can be decomposed according to their colour factors. Out of the seven colour factors, three are of QED-type: $1/N^2$, $N_F/N$ and $N_F^2$. We use the antenna subtraction method to compute…

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

We present a calculation of the bosonic contribution to the two-loop mixed QCD-electroweak scattering amplitudes for $Z$-boson production in association with one hard jet at hadron colliders. We employ a method to calculate amplitudes in…

High Energy Physics - Phenomenology · Physics 2024-09-30 Piotr Bargiela , Fabrizio Caola , Herschel Chawdhry , Xiao Liu

We propose a factorized approach to QED radiative corrections for inclusive and semi-inclusive deep-inelastic scattering to systematically account for QED and QCD radiation contributions to both processes on equal footing. This is achieved…

High Energy Physics - Phenomenology · Physics 2021-12-01 Tianbo Liu , W. Melnitchouk , Jian-Wei Qiu , N. Sato

We compute the electron $g$ factor to the $\mathcal{O}(\alpha^5)$ order on the lattice in quenched QED. We first study finite volume corrections in various IR regularization methods to discuss which regularization is optimal for our…

High Energy Physics - Lattice · Physics 2023-10-17 Ryuichiro Kitano , Hiromasa Takaura

We compute the next-to-leading order (NLO) QCD corrections to the $1 \to 2$ splitting amplitudes in different dimensional regularization (DREG) schemes. Besides recovering previously known results, we explore new DREG schemes and analyze…

High Energy Physics - Phenomenology · Physics 2014-01-15 German F. R. Sborlini , Daniel de Florian , German Rodrigo

We study QED corrections to operator matrix elements involving heavy composite particles (e.g., heavy-mesons, nuclei, and atoms). We define a new notion of reducible and irreducible graphs which is useful for systems with many discrete…

High Energy Physics - Phenomenology · Physics 2025-09-19 Ryan Plestid , Mark B. Wise

Jet substructure has emerged as a critical tool for LHC searches, but studies so far have relied heavily on shower Monte Carlo simulations, which formally approximate QCD at leading-log level. We demonstrate that systematic higher-order QCD…

High Energy Physics - Phenomenology · Physics 2012-09-18 Ilya Feige , Matthew D. Schwartz , Iain W. Stewart , Jesse Thaler

We have calculated the one-loop supersymmetric corrections to the 2 to 2 parton scattering subprocesses antiq q to antiq q, antiq q to g g, g q to g q and g g to g g, including form-factor corrections and box diagrams with internal squarks…

High Energy Physics - Phenomenology · Physics 2009-09-11 John Ellis , Douglas Ross

I discuss recent progress in the calculation of two-loop QCD corrections in the eikonal approximation. I present specific results for the UV structure of the corrections.

High Energy Physics - Phenomenology · Physics 2007-05-23 Nikolaos Kidonakis

We calculate the complete two-loop QCD amplitudes for hadronic $tW$ production by combining analytical and numerical techniques. The amplitudes have been first reduced to master integrals of eight planar and seven non-planar families, which…

High Energy Physics - Phenomenology · Physics 2023-08-02 Long-Bin Chen , Liang Dong , Hai Tao Li , Zhao Li , Jian Wang , Yefan Wang

We explore the relation between resummation and explicit multi-loop calculations for QCD hard-scattering amplitudes. We describe how the factorization properties of amplitudes lead to the exponentiation of double and single poles at each…

High Energy Physics - Phenomenology · Physics 2014-11-17 George Sterman , Maria E. Tejeda-Yeomans

We present the virtual corrections due to the top-quark loops for the process $gg \to ZZ$ at next-to-leading order in QCD. The associated two-loop box diagrams are computed using a small-transverse-momentum expansion. Our results are then…

High Energy Physics - Phenomenology · Physics 2024-04-24 Giuseppe Degrassi , Ramona Gröber , Marco Vitti