English
Related papers

Related papers: Two-loop QCD Amplitudes from the Chiral Algebra Bo…

200 papers

We complete the computation of two-loop helicity amplitudes required to obtain next-to-next-to-leading order QCD corrections for three-jet production at hadron colliders, including all contributions beyond the leading-color approximation.…

High Energy Physics - Phenomenology · Physics 2024-05-15 Giuseppe De Laurentis , Harald Ita , Vasily Sotnikov

It is known that the trace anomaly in the QCD energy-momentum tensor $T^{\mu \nu}$ can be attributed to the anomalies for each of the gauge-invariant quark part and gluon part of $T^{\mu \nu}$, and their explicit three-loop formulas have…

High Energy Physics - Phenomenology · Physics 2023-03-22 Kazuhiro Tanaka

We discuss how higher-point QCD amplitudes may be constructed from lower point ones by imposing the factorization constraints in the limits as external momenta become collinear. As a particular example, the all-$n$ gluon one-loop amplitude…

High Energy Physics - Phenomenology · Physics 2009-09-25 G. Chalmers

Knowledge of two-loop QCD amplitudes for processes $q\bar q \to V_1 V_2 \to (l_1\bar l'_1)(l_2 \bar l'_2)$ is important for improving the theoretical description of four-lepton production in hadron collisions. In this paper we compute these…

High Energy Physics - Phenomenology · Physics 2015-06-22 Fabrizio Caola , Johannes M. Henn , Kirill Melnikov , Alexander V. Smirnov , Vladimir A. Smirnov

We report on the fully analytic calculation of the leading-power contribution to the photon-pion transition form factor $\gamma \, \gamma^{\ast} \to \pi^0$ at two loops in QCD. The applied techniques are based on hard-collinear…

High Energy Physics - Phenomenology · Physics 2021-10-29 Jing Gao , Tobias Huber , Yao Ji , Yu-Ming Wang

We apply a bootstrap procedure to two-loop MHV amplitudes in planar N=4 super-Yang-Mills theory. We argue that the mathematically most complicated part (the $\Lambda^2 B_2$ coproduct component) of the n-particle amplitude is uniquely…

High Energy Physics - Theory · Physics 2015-06-23 John Golden , Marcus Spradlin

We calculate the two-loop QCD corrections to $gg \to ZZ$ involving a closed top-quark loop. We present a new method to systematically construct linear combinations of Feynman integrals with a convergent parametric representation, where we…

High Energy Physics - Phenomenology · Physics 2021-06-16 Bakul Agarwal , Stephen P. Jones , Andreas von Manteuffel

The infrared exponentiation properties of dimensionally-regularized multi-loop scattering amplitudes are typically hidden at the level of the integrand, materializing only after integral evaluation. We address this long-standing problem by…

High Energy Physics - Theory · Physics 2019-07-22 Robert M. Schabinger

The efficient computation of color-summed QCD amplitudes at high parton multiplicities remains a central challenge for precision collider predictions. Existing approaches using trace, color-flow, or adjoint bases suffer from…

High Energy Physics - Phenomenology · Physics 2025-07-31 Oskar Bolinder , Rikkert Frederix , Malin Sjodahl

The leading short-distance contributions to hadronic hard-scattering cross sections in the operator product expansion are described by twist-two quark and gluon operators. The anomalous dimensions of these operators determine the splitting…

High Energy Physics - Phenomenology · Physics 2024-12-02 Thomas Gehrmann , Andreas von Manteuffel , Tong-Zhi Yang

We accomplish for the first time the two-loop computation of the leading-twist contribution to the pion electromagnetic form factor by employing the effective field theory formalism rigorously. The next-to-next-to-leading-order…

High Energy Physics - Phenomenology · Physics 2024-11-07 Yao Ji , Bo-Xuan Shi , Jian Wang , Ye-Fan Wang , Yu-Ming Wang , Hui-Xin Yu

$s$-channel discontinuity of quark-quark scattering amplitude with gluon quantum numbers in the $t$ channel and negative signature is calculated in the Regge kinematical region in the two-loop approximation. Using this discontinuity and…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. S. Fadin , R. Fiore , A. Quartarolo

Witten's twistor string theory has led to new representations of S-matrix in massless QFT as a single object, including Cachazo-He-Yuan formulas in general and connected formulas in four dimensions. As a first step towards more realistic…

High Energy Physics - Theory · Physics 2017-04-05 Song He , Yong Zhang

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 to make use of the off-shell recursive relations with the color-flow decomposition in the calculation of QCD amplitudes on MadGraph. We introduce colored quarks and their interactions with nine gluons in the color-flow basis plus…

High Energy Physics - Phenomenology · Physics 2011-06-08 Kaoru Hagiwara , Yoshitaro Takaesu

Analyzing the pion-mass dependence of $\pi\pi$ scattering phase shifts beyond the low-energy region requires the unitarization of the amplitudes from chiral perturbation theory. In the two-flavor theory, unitarization via the…

High Energy Physics - Phenomenology · Physics 2021-03-17 Malwin Niehus , Martin Hoferichter , Bastian Kubis , Jacobo Ruiz de Elvira

We present the analytic results of one-loop squared amplitudes for $tW$ production at a hadron collider. The calculation is performed using the method of differential equations. After renormalization, we have checked that the infrared…

High Energy Physics - Phenomenology · Physics 2022-08-30 Long-Bin Chen , Liang Dong , Hai Tao Li , Zhao Li , Jian Wang , Yefan Wang

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 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

The rational parts of 6-gluon one-loop amplitudes with scalars circulating in the loop are computed by using the newly developed method for computing the rational parts directly from Feynman integrals. We present the analytic results for…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zhi-Guang Xiao , Gang Yang , Chuan-Jie Zhu