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Related papers: Recent progress for five-particle two-loop scatter…

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We present advances in the development of the numerical unitarity method for the computation of multi-loop amplitudes in QCD. As an application, we show results for all the leading-color two-loop five-gluon helicity amplitudes. The…

High Energy Physics - Phenomenology · Physics 2018-07-26 Samuel Abreu , Fernando Febres Cordero , Harald Ita , Ben Page , Mao Zeng

We use the results of Maher {\em et al.\/} (preceding paper) to construct the matrix of $j=0$ partial-wave two-body and $2\rightarrow3$ scattering amplitudes for the scattering of longitudinally polarized gauge bosons $W_L^\pm$, $Z_L$ and…

High Energy Physics - Phenomenology · Physics 2009-10-22 Loyal Durand , Peter N. Maher , Kurt Riesselmann

We calculate all planar contributions to the two-loop massless helicity amplitudes for the process $q\bar q\to \gamma\gamma\gamma$. The results are presented in fully analytic form in terms of the functional basis proposed recently by…

High Energy Physics - Phenomenology · Physics 2021-08-25 Herschel A. Chawdhry , Michal Czakon , Alexander Mitov , Rene Poncelet

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

The precision frontier in collider physics is being pushed at impressive speed, from both the experimental and the theoretical side. The aim of this review is to give an overview of recent developments in precision calculations within the…

High Energy Physics - Phenomenology · Physics 2021-06-14 Gudrun Heinrich

We prove a lower bound for the modulus of the amplitude for a two-body process at large scattering angle. This is based on the interplay of the analyticity of the amplitude and the positivity properties of its absorptive part. The…

High Energy Physics - Theory · Physics 2019-07-03 Henri Epstein , André Martin

We consider two-loop corrections to $2\to 2$ scattering processes with massive particles in the final state and massive particles in the loop. We discuss the combination of analytic expansions in the high-energy limit and for small…

High Energy Physics - Phenomenology · Physics 2023-06-28 Joshua Davies , Go Mishima , Kay Schönwald , Matthias Steinhauser

We present recent advancements in the computation of three-loop four-particle helicity amplitudes in full-color massless QCD. In this contribution, we focus on the $gg \to \gamma\gamma$ process. We show how to obtain compact analytic…

High Energy Physics - Phenomenology · Physics 2024-10-04 Piotr Bargiela

An overview of the calculation of the two-loop helicity amplitudes for scattering of two gluons into two photons is presented. These matrix elements enter into the recent improved calculation of the QCD background to Higgs boson decay into…

High Energy Physics - Phenomenology · Physics 2010-11-15 Z. Bern , A. De Freitas , L. Dixon

We investigate the high-energy, small-angle limit of two-body gravitational scattering. Using power counting arguments and dispersion relations in an effective field theory for the Regge regime, we derive the general loop expansion that…

High Energy Physics - Theory · Physics 2026-05-21 Francesco Alessio , Vittorio Del Duca , Riccardo Gonzo , Emanuele Rosi , Ira Z. Rothstein , Michael Saavedra

We present an analytic computation of the two-loop QCD corrections to $u\bar{d}\to W^+b\bar{b}$ for an on-shell $W$-boson using the leading colour and massless bottom quark approximations. We perform an integration-by-parts reduction of the…

High Energy Physics - Phenomenology · Physics 2021-10-14 Simon Badger , Heribertus Bayu Hartanto , Simone Zoia

We present numerical results for the two-loop virtual amplitude entering the NNLO corrections to Higgs boson production in association with a top quark pair at the LHC, focusing, as a proof of concept of our method, on the part of the…

High Energy Physics - Phenomenology · Physics 2024-05-31 Bakul Agarwal , Gudrun Heinrich , Stephen P. Jones , Matthias Kerner , Sven Yannick Klein , Jannis Lang , Vitaly Magerya , Anton Olsson

We compute two-loop helicity amplitudes in QCD for diphoton production through quark- and gluon-initiated channels, accounting for a massive internal quark loop by keeping its full mass dependence. Using physical projectors, we directly…

High Energy Physics - Phenomenology · Physics 2025-02-06 Taushif Ahmed , Amlan Chakraborty , Ekta Chaubey , Mandeep Kaur

We employ a scalar model to exemplify the use of contour deformations when solving Lorentz-invariant integral equations for scattering amplitudes. In particular, we calculate the onshell 2 -> 2 scattering amplitude for the scalar system.…

High Energy Physics - Phenomenology · Physics 2019-11-06 Gernot Eichmann , Pedro Duarte , M. T. Peña , Alfred Stadler

We study the amplitudes of the quark scattering by an external electromagnetic field and of the light quark mediated Higgs boson production via gluon fusion in the high-energy limit. The asymptotic behavior of the quark form factors is…

High Energy Physics - Phenomenology · Physics 2022-03-09 Tao Liu , Sneh Modi , Alexander A. Penin

We study the off-shell Higgs data in the process $pp\to h^{(*)} \to Z^{(\ast)}Z^{(\ast)}\to 4\ell$, to constrain deviations of the Higgs couplings. We point out that this channel can be used to resolve the long- and short-distance…

High Energy Physics - Phenomenology · Physics 2015-06-22 Aleksandr Azatov , Christophe Grojean , Ayan Paul , Ennio Salvioni

The production of a Higgs boson in association with a top-antitop quark pair ($t\bar{t}H$) holds significant importance in directly probing the top-quark Yukawa coupling, which is related to various fundamental questions in high energy…

High Energy Physics - Phenomenology · Physics 2024-02-02 Guoxing Wang , Tianya Xia , Li Lin Yang , Xiaoping Ye

We present low-energy theorems for the calculation of loop amplitudes with external scalar or pseudoscalar Higgs bosons which are light compared to the loop particles. Starting from existing lowest-order versions of these theorems, we show…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bernd A. Kniehl , M. Spira

We present a semi-numerical method to compute one-loop corrections to multi-leg processes. We apply the method to the study of Higgs plus four parton and six gluon amplitudes.

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Zanderighi

We present a calculation of the planar two-loop five-gluon amplitudes. The amplitudes are obtained in a variant of the generalized unitarity approach suitable for numerical computations, which we extend for use with finite field…

High Energy Physics - Phenomenology · Physics 2018-06-27 Samuel Abreu , Fernando Febres Cordero , Harald Ita , Ben Page , Mao Zeng