scholarly journals Adjoint BFKL at finite coupling: a short-cut from the collinear limit

2015 ◽  
Vol 2015 (1) ◽  
Author(s):  
Benjamin Basso ◽  
Simon Caron-Huot ◽  
Amit Sever
Keyword(s):  
Collinear Limit

scholarly journals Production of prompt photons associated with jets at LHC in kT-factorization

2019 ◽  
Vol 222 ◽  
pp. 03015
Author(s):  
Maxim Malyshev ◽  
Artem Lipatov ◽  
Hannes Jung
Keyword(s):  
Monte Carlo ◽  
Cross Sections ◽  
Parton Shower ◽  
Gluon Fusion ◽  
Monte Carlo Generator ◽  
Hadronic Jets ◽  
Factorization Approach ◽  
Associated Production ◽  
Parton Showering ◽  
Collinear Limit

We use the kT–factorization approach to calculate total and differential cross sections of associated production of prompt photons and hadronic jets at the LHC energies. Our consideration relies on the pegasus Monte-Carlo generator with implemented ℴ(αα2s) off-shell gluon–gluon fusion subprocess g*g* → γqq− and several subleading quark-initiated contributions from ℴ(ααs) and ℴ(αα2s) subprocesses, taken into account in the collinear limit. Using Monte-Carlo generators CASCADE and PYTHIA, we investigate parton showering effects and compare our predictions with the data, taken by CMS and ATLAS collaborations at the LHC. We demostrate reasonabledescription of the data and the importance of parton shower effects in the kT–factorization.

scholarly journals Subleading terms in the collinear limit of Yang–Mills amplitudes

2015 ◽  
Vol 750 ◽  
pp. 587-590 ◽  
Author(s):  
Stephan Stieberger ◽  
Tomasz R. Taylor
Keyword(s):  
Yang Mills ◽  
Collinear Limit

scholarly journals Groomed jet mass as a direct probe of collinear parton dynamics

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Daniele Anderle ◽  
Mrinal Dasgupta ◽  
Basem Kamal El-Menoufi ◽  
Marco Guzzi ◽  
Jack Helliwell
Keyword(s):  
Mass Distribution ◽  
Leading Order ◽  
Order Calculation ◽  
Fixed Order ◽  
Collinear Limit

AbstractWe study the link between parton dynamics in the collinear limit and the logarithmically enhanced terms of the groomed jet mass distribution, for jets groomed with the modified mass-drop tagger (mMDT). While the leading-logarithmic (LL) result is linked to collinear evolution with leading-order splitting kernels, here we derive the NLL structure directly from triple-collinear splitting kernels. The calculation we present is a fixed-order calculation in the triple-collinear limit, independent of resummation ingredients and methods. It therefore constitutes a powerful cross-check of the NLL results previously derived using the SCET formalism and provides much of the insight needed for resummation within the traditional QCD approach.

scholarly journals Massive event-shape distributions at N2LL

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Alejandro Bris ◽  
Vicent Mateu ◽  
Moritz Preisser
Keyword(s):  
Cross Sections ◽  
Numerical Study ◽  
Renormalization Group Equation ◽  
Effective Theory ◽  
Event Shape ◽  
Group Equation ◽  
Soft Collinear Effective Theory ◽  
Fixed Order ◽  
Collinear Limit ◽  
Event Shapes

Abstract In a recent paper we have shown how to optimally compute the differential and cumulative cross sections for massive event-shapes at $$ \mathcal{O}\left({\alpha}_s\right) $$ O α s in full QCD. In the present article we complete our study by obtaining resummed expressions for non-recoil-sensitive observables to N2LL + $$ \mathcal{O}\left({\alpha}_s\right) $$ O α s precision. Our results can be used for thrust, heavy jet mass and C-parameter distributions in any massive scheme, and are easily generalized to angularities and other event shapes. We show that the so-called E- and P-schemes coincide in the collinear limit, and compute the missing pieces to achieve this level of accuracy: the P-scheme massive jet function in Soft-Collinear Effective Theory (SCET) and boosted Heavy Quark Effective Theory (bHQET). The resummed expression is subsequently matched into fixed-order QCD to extend its validity towards the tail and far- tail of the distribution. The computation of the jet function cannot be cast as the dis- continuity of a forward-scattering matrix element, and involves phase space integrals in d = 4 − 2ε dimensions. We show how to analytically solve the renormalization group equation for the P-scheme SCET jet function, which is significantly more complicated than its 2-jettiness counterpart, and derive rapidly-convergent expansions in various kinematic regimes. Finally, we perform a numerical study to pin down when mass effects become more relevant.

scholarly journals N-jettiness beam functions at N3LO

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Markus A. Ebert ◽  
Bernhard Mistlberger ◽  
Gherardo Vita
Keyword(s):  
Higgs Boson ◽  
Cross Sections ◽  
Production Cross ◽  
Building Blocks ◽  
Leading Order ◽  
Collinear Limit ◽  
Complete Calculation ◽  
The One ◽  
Class Of Functions ◽  
Rational Kernels

Abstract We present the first complete calculation for the quark and gluon N-jettiness ($$ {\mathcal{T}}_N $$ T N ) beam functions at next-to-next-to-next-to-leading order (N3LO) in perturbative QCD. Our calculation is based on an expansion of the differential Higgs boson and Drell-Yan production cross sections about their collinear limit. This method allows us to employ cutting edge techniques for the computation of cross sections to extract the universal building blocks in question. The class of functions appearing in the matching coefficents for all channels includes iterated integrals with non-rational kernels, thus going beyond the one of harmonic polylogarithms. Our results are a key step in extending the $$ {\mathcal{T}}_N $$ T N subtraction methods to N3LO, and to resum $$ {\mathcal{T}}_N $$ T N distributions at N3LL′ accuracy both for quark as well as for gluon initiated processes.

scholarly journals Transverse momentum dependent PDFs at N3LO

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Markus A. Ebert ◽  
Bernhard Mistlberger ◽  
Gherardo Vita
Keyword(s):  
Transverse Momentum ◽  
Cross Sections ◽  
Production Cross ◽  
Gluon Fusion ◽  
Building Blocks ◽  
Distribution Functions ◽  
Leading Order ◽  
Parton Distribution Functions ◽  
Transverse Momentum Dependent ◽  
Collinear Limit

Abstract We compute the quark and gluon transverse momentum dependent parton distribution functions at next-to-next-to-next-to-leading order (N3LO) in perturbative QCD. Our calculation is based on an expansion of the differential Drell-Yan and gluon fusion Higgs production cross sections about their collinear limit. This method allows us to employ cutting edge multiloop techniques for the computation of cross sections to extract these universal building blocks of the collinear limit of QCD. The corresponding perturbative matching kernels for all channels are expressed in terms of simple harmonic polylogarithms up to weight five. As a byproduct, we confirm a previous computation of the soft function for transverse momentum factorization at N3LO. Our results are the last missing ingredient to extend the qT subtraction methods to N3LO and to obtain resummed qT spectra at N3LL′ accuracy both for gluon as well as for quark initiated processes.

scholarly journals Three point energy correlators in the collinear limit: symmetries, dualities and analytic results

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Hao Chen ◽  
Ming-Xing Luo ◽  
Ian Moult ◽  
Tong-Zhi Yang ◽  
Xiaoyuan Zhang ◽  
...  
Keyword(s):  
Point Energy ◽  
Collinear Limit

scholarly journals Evaluating the six-point remainder function near the collinear limit

2014 ◽  
Vol 29 (27) ◽  
pp. 1450154 ◽  
Author(s):  
Georgios Papathanasiou
Keyword(s):  
Scattering Amplitudes ◽  
High Energy Phys ◽  
Bound State ◽  
High Energy ◽  
Recent Proposal ◽  
Computational Tools ◽  
Yang Mills ◽  
Remainder Function ◽  
Leading Term ◽  
Collinear Limit

The simplicity of maximally supersymmetric Yang–Mills theory makes it an ideal theoretical laboratory for developing computational tools, which eventually find their way to QCD applications. In this contribution, we continue the investigation of a recent proposal by Basso, Sever and Vieira, for the nonperturbative description of its planar scattering amplitudes, as an expansion around collinear kinematics. The method of G. Papathanasiou, J. High Energy Phys.1311, 150 (2013), arXiv:1310.5735, for computing the integrals the latter proposal predicts for the leading term in the expansion of the six-point remainder function, is extended to one of the subleading terms. In particular, we focus on the contribution of the two-gluon bound state in the dual flux tube picture, proving its general form at any order in the coupling, and providing explicit expressions up to six loops. These are included in the ancillary file accompanying the version of this paper on the arXiv.

scholarly journals Factorization of tree QCD amplitudes in the high-energy limit and in the collinear limit

2000 ◽  
Vol 568 (1-2) ◽  
pp. 211-262 ◽  
Author(s):  
Vittorio Del Duca ◽  
Alberto Frizzo ◽  
Fabio Maltoni
Keyword(s):  
High Energy ◽  
Energy Limit ◽  
High Energy Limit ◽  
Collinear Limit
Sign in / Sign up

Export Citation Format

Share Document