English
Related papers

Related papers: Two-loop amplitudes for e+ e- -> q qbar g: the nf-…

200 papers

We present a new method for computing multi-loop scattering amplitudes in Quantum Field Theory. It extends the Generalized Unitarity method by constraining not only the integrand of the amplitude but also its full integrated form. Our…

High Energy Physics - Theory · Physics 2025-12-18 Piotr Bargiela

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 compute the corrections to the two-loop amplitudes for $gg \to h$, $gg \to hg$, $qg \to hq$, and $q \bar q \to hg$ due to a modified cubic Higgs self-coupling. The exact dependence on the Higgs and top-quark masses across the entire $2…

High Energy Physics - Phenomenology · Physics 2024-10-23 Ulrich Haisch , Marco Niggetiedt

We provide two two-loop amplitudes relevant for precision Higgs physics. The first is the two-loop amplitude for Higgs boson production through gluon fusion with exact dependence on the top quark mass up to squared order in the dimensional…

High Energy Physics - Phenomenology · Physics 2020-08-26 Charalampos Anastasiou , Nicolas Deutschmann , Armin Schweitzer

The study of collinear behavior for gauge theories in the spacelike region is of great phenomenological and theoretical importance. We analytically calculate the two-loop spacelike splitting amplitude for the full color N=4 Super-Yang-Mills…

High Energy Physics - Theory · Physics 2024-08-06 Johannes Henn , Rourou Ma , Yongqun Xu , Kai Yan , Yang Zhang , Hua Xing Zhu

The factorisation of QCD matrix elements in the limit of two external partons becoming collinear is described by process-independent splitting amplitudes, which can be expanded systematically in perturbation theory. Working in conventional…

High Energy Physics - Phenomenology · Physics 2015-06-23 Claude Duhr , Thomas Gehrmann , Matthieu Jaquier

We derive the analytic expression of the two one-loop dipole contributions to the elastic 4-gluon amplitude in QCD. The first one corresponds to the double QCD pomeron exchange, the other to an order alpha^2 correction to one-pomeron…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. Navelet , R. Peschanski

A general formalism for computing only the rational parts of oneloop QCD amplitudes is developed. Starting from the Feynman integral representation of the one-loop amplitude, we use tensor reduction and recursive relations to compute the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Zhi-Guang Xiao , Gang Yang , Chuan-Jie Zhu

NLO scattering amplitudes are provided by fully automated numerical tools, such as OpenLoops, for a very wide range of processes. In order to match the numerical precision of current and future collider experiments, the higher precision of…

High Energy Physics - Phenomenology · Physics 2022-07-18 Stefano Pozzorini , Natalie Schär , Max F. Zoller

We present a generalisation of the double-logarithmic equation for the anomalous dimension of the non-singlet unpolarized twist-2 operators in QCD. Using the known three-loop result, this generalisation allows to predict a small x expansion…

High Energy Physics - Phenomenology · Physics 2017-12-01 V. N. Velizhanin

An explicit investigation about the equal-mass two-loop sunrise Feynman graph is performed. Such perturbative amplitude is related with many important physical process treated in the standard model context. The background of this…

High Energy Physics - Phenomenology · Physics 2022-11-15 G. Dallabona , O. A. Battistel

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

We present complete analytical ${\mathcal O}(\epsilon^2)$ results on the one-loop amplitudes relevant for the NNLO quark-parton model description of the hadroproduction of heavy quarks as given by the so-called loop-by-loop contributions.…

High Energy Physics - Phenomenology · Physics 2016-08-16 J. G. Körner , Z. Merebashvili , M. Rogal

We propose a compact analytic expression for the polylogarithmic part of the n-point two-loop all-plus helicity amplitude in gauge theory.

High Energy Physics - Theory · Physics 2016-07-20 David C. Dunbar , Guy R. Jehu , Warren B. Perkins

We compute the ${\cal O}(\alpha_s^3)$ virtual QCD corrections to the $\gamma^*\to q\bar q g$ matrix element arising from the interference of the two-loop with the tree-level amplitude and from the self-interference of the one-loop…

High Energy Physics - Phenomenology · Physics 2010-04-06 L. W. Garland , T. Gehrmann , E. W. N. Glover , A. Koukoutsakis , E. Remiddi

We present a precise and efficient computation of the two-loop amplitudes entering the Higgs boson pair production process via gluon fusion. Our approach is based on the small-Higgs-mass expansion while keeping the full dependence on the…

High Energy Physics - Phenomenology · Physics 2021-09-29 Guoxing Wang , Yuxuan Wang , Xiaofeng Xu , Yongqi Xu , Li Lin Yang

We present a method for the integrand-level reduction of two-loop helicity amplitudes in both $d=4-2\epsilon$ and $d=4$ dimensions. The amplitude is expressed in terms of a set of Feynman integrals and their coefficients that depend on the…

High Energy Physics - Phenomenology · Physics 2025-11-14 Giuseppe Bevilacqua , Dhimiter Canko , Costas Papadopoulos , Aris Spourdalakis

I discuss the recent advances in the computation of two-loop scattering amplitudes for five-particle processes. The latter are fundamental ingredients to obtain predictions at the next-to-next-to-leading order (NNLO) in QCD for many…

High Energy Physics - Phenomenology · Physics 2023-10-09 Simone Zoia

We present the analytical results of the two-loop amplitudes for hadronic $tW$ production, focusing on the leading color and light fermion-loop contributions. The calculation of the two-loop integrals is performed using the method of…

High Energy Physics - Phenomenology · Physics 2022-12-14 Long-Bin Chen , Liang Dong , Hai Tao Li , Zhao Li , Jian Wang , Yefan Wang

The computation of two-loop amplitudes for the production of multiple Higgs and electroweak gauge bosons via gluon fusion with exact dependence on quark masses relies primarily on numerical methods. We propose a framework that enables their…

High Energy Physics - Phenomenology · Physics 2024-11-13 Charalampos Anastasiou , Julia Karlen , George Sterman , Aniruddha Venkata
‹ Prev 1 3 4 5 6 7 10 Next ›