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Related papers: Two-Loop Amplitudes for Gluon Fusion into Two Phot…

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The calculation of the next-to-leading order QCD corrections to the production of a neutral Higgs-boson pair is briefly summarized. The dominant production mechanism is gluon fusion via top-quark loops, so that the QCD corrections can be…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Dawson , S. Dittmaier , M. Spira

We review the current status of high-multiplicity double-virtual QCD corrections to processes relevant for LHC phenomenology. In particular, we discuss the recent full-color calculation of the five-parton process, whose two-loop amplitudes…

High Energy Physics - Phenomenology · Physics 2024-06-27 Giuseppe De Laurentis

We compute the two-loop massless QCD corrections to the helicity amplitudes for the production of two electroweak gauge bosons in the gluon fusion channel, $gg \to V_1 V_2$, keeping the virtuality of the vector bosons $V_1$ and $V_2$…

High Energy Physics - Phenomenology · Physics 2015-09-14 Andreas von Manteuffel , Lorenzo Tancredi

We review the current state-of-the-art in integrand level reduction for five-point scattering amplitudes at two loops in QCD. We present some benchmark results for the evaluation of the leading colour two-loop five-gluon amplitudes in the…

We present an explicit expression for a particular $n$-gluon two loop scattering partial amplitude. Specifically we present an analytic form for the single trace $N_c$ independent colour partial amplitude for the case where all external…

High Energy Physics - Phenomenology · Physics 2020-04-08 David C. Dunbar , Warren B. Perkins , Joseph M. W. Strong

We study the factorisation properties of one-loop scattering amplitudes in the triple collinear limit and extract the universal splitting amplitudes for processes initiated by a gluon. The splitting amplitudes are derived from the analytic…

High Energy Physics - Phenomenology · Physics 2015-07-20 Simon Badger , Francesco Buciuni , Tiziano Peraro

In high energy hadronic collisions a scalar or pseudoscalar Higgs boson, Phi=H,A, can be efficiently produced via gluon fusion, which is mediated by heavy quark loops. We here consider double real emission corrections to Phi=A production,…

High Energy Physics - Phenomenology · Physics 2015-05-20 Francisco Campanario , Michael Kubocz , Dieter Zeppenfeld

We present the two-loop QCD amplitude for the interaction of two gluons and a CP-even Higgs boson in the Minimal Supersymmetric Standard Model. We apply a novel numerical method for the evaluation of Feynman diagrams with infrared,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Charalampos Anastasiou , Stefan Beerli , Alejandro Daleo

We present the two-loop virtual QCD corrections to the production of heavy quarks in gluon fusion. The results are exact in the limit when all kinematical invariants are large compared to the mass of the heavy quark up to terms suppressed…

High Energy Physics - Phenomenology · Physics 2010-04-05 M. Czakon , A. Mitov , S. Moch

We consider the three-loop scattering amplitudes for the production of a pair of photons in quark-antiquark annihilation in Quantum Chromodynamics (QCD). We use suitably defined projectors to efficiently calculate all helicity amplitudes.…

High Energy Physics - Phenomenology · Physics 2021-03-24 Fabrizio Caola , Andreas von Manteuffel , Lorenzo Tancredi

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 present the first full analytic evaluation of the scattering amplitude for the process $q {\bar q} \to Q {\bar Q}$ up-to two loops in Quantum Chromodynamics, for a massless $(q)$ and a massive $(Q)$ quark flavour. The interference terms…

High Energy Physics - Phenomenology · Physics 2022-09-28 Manoj K. Mandal , Pierpaolo Mastrolia , Jonathan Ronca , William J. Torres Bobadilla

We present the O(alpha_s^4) virtual QCD corrections to gluon-gluon scattering due to the interference of tree and two-loop amplitudes. We work in conventional dimensional regularisation and give analytic expressions renormalised in the…

High Energy Physics - Phenomenology · Physics 2010-04-06 E. W. N. Glover , C. Oleari , M. E. Tejeda-Yeomans

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

The couplings of Higgs particles to two photons are analyzed in the threshold region, where the Higgs mass is about twice the loop--particle mass leading to possible bound state formation. The amplitude of the pseudoscalar decay $A\to…

High Energy Physics - Phenomenology · Physics 2009-10-28 Kirill Melnikov , Michael Spira , Oleg Yakovlev

I present the computation of the two-loop amplitudes for the scattering of a lepton pair with an off-shell and an on-shell photon in massless QED. We apply modern techniques developed to tackle QCD amplitudes with many scales: we express…

High Energy Physics - Phenomenology · Physics 2024-05-15 Simone Zoia

The imaginary part of the Feynman amplitude of the $W$-loop contribution to the Higgs decay into two gammas (viewed as a function of the square of the off shell Higgs momentum) is finite and unambiguous. It is presented as the product of an…

High Energy Physics - Phenomenology · Physics 2015-10-08 Ekaterina Christova , Ivan Todorov

The coupling of the Higgs to second generation particles can be studied by measuring the decay of the Higgs boson to two muons. In this analysis we considered the process at a centre of mass energy of 1 TeV, where the WW-fusion process is…

High Energy Physics - Experiment · Physics 2016-03-17 Michele Faucci Giannelli , Sara Celani

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

QCD radiative correction to Higgs $\rightarrow$ two photons decay rate is calculated. Below the threshold we found negligible correction, thus supporting results obtained earlier by Djouadi et all [7]. Above the threshold radiative…

High Energy Physics - Phenomenology · Physics 2009-10-22 K. Melnikov , O. Yakovlev