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Related papers: Unitarity-based Techniques for One-Loop Calculatio…

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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 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

QCD one-loop corrections to the semileptonic process $e^+ e^- \to \mu^- \bar \nu_\mu u \bar d$ are computed. We compare the exact calculation with a ``naive'' approach to strong radiative corrections which has been widely used in the…

High Energy Physics - Phenomenology · Physics 2009-10-28 E. Maina , R. Pittau , M. Pizzio

We suggest a new approach for the automatic and fully numerical evaluation of one-loop scattering amplitudes in perturbative quantum field theory. We use suitably formulated dispersion relations to perform the calculation as a convolution…

High Energy Physics - Phenomenology · Physics 2008-09-29 M. Moretti , F. Piccinini , A. D. Polosa

I review the recent progress in the evaluation of two-loop massive QCD amplitudes necessary for the description of hadronic scattering processes at the LHC. I put a special emphasis on the case of top-quark final states.

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Czakon

QCD is an extensively developed and tested gauge theory, which models the strong interactions in the high-energy regime. In this talk, I shall review the considerable progress which has been achieved in the last few years in the most…

High Energy Physics - Phenomenology · Physics 2008-11-26 Vittorio Del Duca

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

We use functional methods to compute one-loop effects in Heavy Quark Effective Theory. The covariant derivative expansion technique facilitates the efficient extraction of matching coefficients and renormalization group evolution equations.…

High Energy Physics - Phenomenology · Physics 2020-07-15 Timothy Cohen , Marat Freytsis , Xiaochuan Lu

A brief review of various numerical techniques used in loop quantum cosmology and results is presented. These include the way extensive numerical simulations shed insights on the resolution of classical singularities, resulting in the key…

General Relativity and Quantum Cosmology · Physics 2013-07-11 Parampreet Singh

We present results for the O(alpha_s) virtual corrections to q g -> W b bbar q' obtained with a new automatized approach to the evaluation of one-loop amplitudes in terms of Feynman diagrams. Together with the O(alpha_s) corrections to q q'…

High Energy Physics - Phenomenology · Physics 2015-05-30 Laura Reina , Thomas Schutzmeier

Quantum process tomography (QPT) methods aim at identifying a given quantum process. The present paper focuses on the estimation of a unitary process. This class is of particular interest because quantum mechanics postulates that the…

Quantum Physics · Physics 2024-01-23 François Verdeil , Yannick Deville

We present the three loop contribution (order $e^4$) to the pressure of massless quantum electrodynamics at nonzero temperature. The calculation is performed within the imaginary time formalism. Dimensional regularization is used to handle…

High Energy Physics - Phenomenology · Physics 2014-11-17 Claudio Coriano` , Rajesh Parwani

We discuss new results in QCD obtained with string-based methods. These methods were originally derived from superstring theory and are significantly more efficient than conventional Feynman rules. This technology was a key ingredient in…

High Energy Physics - Theory · Physics 2007-05-23 Z. Bern , L. Dixon , D. A. Kosower

Scattering amplitudes for the massless QCD process, $q\bar{q}\to q^\prime\bar{q}^\prime$, are calculated in the one-loop order in the Feynman-Diagram (FD) gauge, where gluons are quantized on the light cone with opposite direction of the…

High Energy Physics - Phenomenology · Physics 2024-07-17 Kaoru Hagiwara , Kentarou Mawatari , Youichi Yamada , Ya-Juan Zheng

These notes are a short introduction to the pinch technique. We present the one-loop calculations for basic QCD Green's functions. The equivalence between the pinch technique and the background field method is explicitly shown at the…

High Energy Physics - Phenomenology · Physics 2008-02-01 Vincent Mathieu

We study the full contributions at the leading order(LO) and QCD next-to-leading order(NLO) to the cross section of the \eewwbb process in the standard model(SM) at the ILC. In dealing the resonance problem we adopted the complex mass…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guo Lei , Ma Wen-Gan , Zhang Ren-You , Wang Shao-Ming

In this article we discuss the calculation of single top-quark production in the t channel at two-loop order in QCD. In particular we present the decomposition of the amplitude according to its spin and colour structure and present complete…

High Energy Physics - Phenomenology · Physics 2014-12-22 M. Assadsolimani , P. Kant , B. Tausk , P. Uwer

A summary is presented of the most recent matrix elements for massless 2 to 2 scattering processes calculated at two loops in QCD perturbation theory together with a brief review on the calculational methods and techniques used.

High Energy Physics - Phenomenology · Physics 2009-11-07 Maria Elena Tejeda-Yeomans

QCD one-loop corrections to the full gauge invariant set of electroweak diagrams describing the hadronic process $e^+ e^- \to u~\bar d~s~\bar c$ are computed. Four-jet shape variables for $WW$ events are studied at next-to-leading order and…

High Energy Physics - Phenomenology · Physics 2011-02-01 E. Maina , R. Pittau , M. Pizzio

I review the recent work on obtaining precise estimates of higher-order corrections in QCD and field theory.

High Energy Physics - Phenomenology · Physics 2007-05-23 Marek Karliner