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Related papers: The soft-gluon current at one-loop order

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We investigate the breakdown of collinear factorization for non-inclusive observables in hadron-hadron collisions. For pure QCD processes, factorization is violated at the three-loop level and it has a structure identical to that…

High Energy Physics - Phenomenology · Physics 2015-06-05 Jeffrey R. Forshaw , Michael H. Seymour , Andrzej Siodmok

We report on further progress in understanding soft singularities of massless gauge theory scattering amplitudes. Recently, a set of equations was derived based on Sudakov factorization, constraining the soft anomalous dimension matrix of…

High Energy Physics - Phenomenology · Physics 2011-08-17 Lance J. Dixon , Einan Gardi , Lorenzo Magnea

We recompute the functions describing the collinear factorization of one-loop amplitudes using the unitarity-based method. We present the results in a form suitable for use as an ingredient in two-loop calculations. We also present a…

High Energy Physics - Phenomenology · Physics 2008-11-26 David A. Kosower , Peter Uwer

Perturbative QCD relates the single transverse-spin asymmetries (SSAs) for hard processes at large transverse-momentum of produced particle to partonic matrix elements that describe interference between scattering from a coherent…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yuji Koike , Kazuhiro Tanaka

The amplitude for multiple soft gluon emissions, ordered in their relative softness, can be written as a product of infrared (IR) divergent loop-expanded soft gluon currents and the matrix elements. In a more recent work, Angeles-Martinez,…

High Energy Physics - Phenomenology · Physics 2022-08-18 Aditya Pathak

We use on-shell recursion relations to compute analytically the one-loop corrections to maximally-helicity-violating n-gluon amplitudes in QCD. The cut-containing parts have been computed previously; our work supplies the remaining rational…

High Energy Physics - Phenomenology · Physics 2008-11-26 Carola F. Berger , Zvi Bern , Lance J. Dixon , Darren Forde , David A. Kosower

Recently the calculations of all five-parton one-loop QCD amplitudes have been completed. In this letter we describe how to get the corresponding amplitudes with one gluon replaced by a photon and we give the explicit results for the…

High Energy Physics - Phenomenology · Physics 2009-10-28 Adrian Signer

We combine the six-dimensional helicity formalism of Cheung and O'Connell with D-dimensional generalized unitarity to obtain a new formalism for computing one-loop amplitudes in dimensionally regularized QCD. With this procedure, we…

High Energy Physics - Phenomenology · Physics 2013-05-29 Scott Davies

We address the problem of decomposing graphs in perturbative QCD into terms associated with particular regions. Motivated by asking how to incorporate next-to-leading order (NLO) QCD corrections in parton-shower algorithms, we require that:…

High Energy Physics - Phenomenology · Physics 2010-02-03 J. C. Collins , F. Hautmann

Homogeneous power counting in Non-Relativistic QCD (NRQCD) implies the simultaneous existence of both soft and ultrasoft gluons. In the velocity renormalization group (vNRQCD) formalism we show that operators involving soft fields…

High Energy Physics - Phenomenology · Physics 2019-01-31 Ira Z. Rothstein , Prashant Shrivastava , Iain W. Stewart

The rational parts of 5-gluon one-loop amplitudes are computed by using the newly developed method for computing the rational parts directly from Feynman integrals. We found complete agreement with the previously well-known results of Bern,…

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

We develop a new systematic procedure for the Regge limit in perturbative QCD to arbitrary logarithmic order. The formalism relies on the IR structure and the gauge symmetry of the theory. We identify leading regions in loop momentum space…

High Energy Physics - Phenomenology · Physics 2009-11-10 Tibor Kucs

We generalise the factorization of abelian gauge theory amplitudes to next-to-leading power (NLP) in a soft scale expansion, following a recent generalisation for Yukawa theory. From an all-order power counting analysis of leading and…

High Energy Physics - Phenomenology · Physics 2021-03-01 E. Laenen , J. Sinninghe Damsté , L. Vernazza , W. Waalewijn , L. Zoppi

We determine the three-loop form factor parameterising the amplitude for the production of an off-shell Higgs boson in gluon fusion in QCD with a single massive quark. The result is obtained via a numerical solution of a system of…

High Energy Physics - Phenomenology · Physics 2020-06-04 M. Czakon , M. Niggetiedt

We consider QCD corrections to Higgs boson production through gluon-gluon fusion in hadron collisions. Using the recently evaluated two-loop amplitude for this process and the corresponding factorization formulae for soft-gluon…

High Energy Physics - Phenomenology · Physics 2010-02-03 S. Catani , D. de Florian , M. Grazzini

After briefly introducing the framework of QCD factorization for B-> M1 M2 in the language of the Soft-Collinear Effective Theory, we firstly address the recent efforts on higher-order radiative corrections in QCD factorization. Then we…

High Energy Physics - Phenomenology · Physics 2014-11-20 Deshan Yang

In this thesis we present an introduction to Soft-Collinear Effective Theory, which can be used to prove (or disprove) factorization theorems to all orders in the strong coupling constant for some B decays into light and energetic…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bjorn O Lange

We review the state-of-the-art knowledge of IR singularities in multileg QCD amplitudes, identifying the key reasons for the remarkable simplicity of the soft anomalous dimension. We then present a novel strategy to compute this quantity…

High Energy Physics - Phenomenology · Physics 2026-04-22 Einan Gardi , Zehao Zhu

A general discussion is presented of the single logarithmic soft factor that appears in two scale QCD observables in processes involving four partons. We treat it as the ``fifth form factor'', accompanying the four collinear singular…

High Energy Physics - Phenomenology · Physics 2009-11-11 Yu. L. Dokshitzer , G. Marchesini

We obtain an exact result for the soft gluon production and its p_T distribution due to a gluon loop in a constant chromo-electric background field E^a with arbitrary color. Unlike Schwinger's result for e^+e^- pair production in QED which…

High Energy Physics - Phenomenology · Physics 2009-11-11 Gouranga C. Nayak , Peter van Nieuwenhuizen