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Related papers: Matching Parton Showers to NLO Computation

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The dipole formalism provides a powerful framework from which parton showers can be constructed. In a recent paper, we proposed a dipole shower with improved colour accuracy and in this paper we show how it can be further improved. After an…

High Energy Physics - Phenomenology · Physics 2021-04-29 Jack Holguin , Jeffrey R. Forshaw , Simon Plätzer

We consider $ZZ$ production in hadronic collisions and present state-of-the-art predictions in QCD perturbation theory matched to parton showers. Next-to-next-to-leading order corrections to the quark-initiated channel are combined with…

High Energy Physics - Phenomenology · Physics 2022-02-02 Luca Buonocore , Gabriël Koole , Daniele Lombardi , Luca Rottoli , Marius Wiesemann , Giulia Zanderighi

The method to merge matrix elements for multi particle production and parton showers in electron-positron annihilations and hadronic collisions and its implementation into the new event generator SHERPA is described in detail. Examples…

High Energy Physics - Phenomenology · Physics 2009-11-11 Andreas Schaelicke , Frank Krauss

Modern parton showers are built using one of two models: dipole showers or angular ordered showers. Both have distinct strengths and weaknesses. Dipole showers correctly account for wide-angle, soft gluon emissions and track the leading…

High Energy Physics - Phenomenology · Physics 2020-09-02 Jeffrey R. Forshaw , Jack Holguin , Simon Plätzer

In the present work we consider the assignment of the factorization and renormalization scales in hadron collider processes with associated jet production, at next-to-leading order (NLO) in perturbation theory. We propose a simple, definite…

High Energy Physics - Phenomenology · Physics 2015-06-05 Keith Hamilton , Paolo Nason , Giulia Zanderighi

Parton showers are among the most widely used tools in collider physics. Despite their key importance, none so far has been able to demonstrate accuracy beyond a basic level known as leading logarithmic (LL) order, with ensuing limitations…

High Energy Physics - Phenomenology · Physics 2020-08-05 Mrinal Dasgupta , Frédéric A. Dreyer , Keith Hamilton , Pier Francesco Monni , Gavin P. Salam , Gregory Soyez

We present a study of the results obtained combining LO partonic matrix elements with different orders of partons distributions. These are compared to the best prediction using NLO for both matrix elements and parton distributions. The aim…

High Energy Physics - Phenomenology · Physics 2007-06-15 R. S. Thorne , A. Sherstnev , C. Gwenlan

We report on a method for matching the next-to-leading order calculation of QCD jet production in e+e- annihilation with a Monte Carlo parton shower event generator (MC) to produce realistic final states. The final result is accurate to…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michael Krämer , Stephen Mrenna , Davison E. Soper

As part of a programme to develop parton showers with controlled logarithmic accuracy, we consider the question of collinear spin correlations within the PanScales family of parton showers. We adapt the well-known Collins-Knowles…

High Energy Physics - Phenomenology · Physics 2021-08-18 Alexander Karlberg , Gavin P. Salam , Ludovic Scyboz , Rob Verheyen

The interpretation of experimental measurements at the LHC requires accurate theoretical predictions for exclusive observables, and in particular the summation of soft and collinear radiation to all orders in perturbation theory. We report…

High Energy Physics - Phenomenology · Physics 2015-02-13 Michael Czakon , Michael Krämer , Malgorzata Worek

We present the CoLoRFulNNLO method to compute higher order radiative corrections to jet cross sections in perturbative QCD. We apply our method to the computation of event shape observables in electron-positron collisions at NNLO accuracy…

High Energy Physics - Phenomenology · Physics 2016-10-19 Vittorio Del Duca , Claude Duhr , Adam Kardos , Gábor Somogyi , Zoltán Szőr , Zoltán Trócsányi , Zoltán Tulipánt

We present a new implementation of the NNLO QCD corrections to three-jet final states and related event-shape observables in electron--positron annihilation. Our implementation is based on the antenna subtraction method, and is performed in…

High Energy Physics - Phenomenology · Physics 2017-12-06 Thomas Gehrmann , Nigel Glover , Alexander Huss , Jan Niehues , Hantian Zhang

The project of constructing a complete NLO-level Parton Shower Monte Carlo for the QCD processes developed in IFJ PAN in Krakow is reviewed. Four issues are discussed: (1) the extension of the standard inclusive collinear factorization into…

High Energy Physics - Phenomenology · Physics 2011-11-24 M. Skrzypek , S. Jadach , A. Kusina , W. Placzek , M. Slawinska , O. Gituliar

Vector-boson fusion and associated production at the LHC can provide key information on the strength and structure of the Higgs couplings to the Standard Model particles. Using an effective field theory approach, we study the effects of…

High Energy Physics - Phenomenology · Physics 2015-06-17 Fabio Maltoni , Kentarou Mawatari , Marco Zaro

This lecture discusses the physics implemented by Monte Carlo event generators for hadron colliders. It details the construction of parton showers and the matching of parton showers to fixed-order calculations at higher orders in…

High Energy Physics - Phenomenology · Physics 2015-06-19 Stefan Höche

We present a calculation of the next-to-leading order (NLO) QCD corrections to gluon-induced electroweak gauge boson pair production, $gg \to ZZ$ and $gg \to W^+W^-$, matched to the PYTHIA8 parton shower in the POWHEG approach. The…

High Energy Physics - Phenomenology · Physics 2021-08-18 Simone Alioli , Silvia Ferrario Ravasio , Jonas M. Lindert , Raoul Röntsch

We show how a careful analysis of the behaviour of a parton shower Monte Carlo in the vicinity of the soft and collinear regions allows one to formulate a modified MC@NLO-matching prescription that reduces the number of negative-weight…

High Energy Physics - Phenomenology · Physics 2020-08-26 R. Frederix , S. Frixione , S. Prestel , P. Torrielli

We consider the production of a pair of heavy quarks and illustrate the derivation of the MiNNLO method to match next-to-next-to-leading order calculations with parton showers (NNLO+PS) for this class of processes. As a first application,…

High Energy Physics - Phenomenology · Physics 2022-05-04 Javier Mazzitelli , Pier Francesco Monni , Paolo Nason , Emanuele Re , Marius Wiesemann , Giulia Zanderighi

Parton shower algorithms are key components of theoretical predictions for high-energy collider physics. Work towards more accurate parton shower algorithms is thus pursued along many different avenues. The systematic treatment of…

High Energy Physics - Phenomenology · Physics 2019-01-23 Joshua Isaacson , Stefan Prestel

We present predictions for hadronic decays of the Higgs boson at next-to-next-to-leading order (NNLO) in QCD matched with parton shower based on the POWHEG framework. Those include decays into bottom quarks with full bottom-quark mass…

High Energy Physics - Phenomenology · Physics 2021-11-01 YaLu Hu , ChuanLe Sun , Xiao-Min Shen , Jun Gao