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Related papers: Initial State Parton Showers Beyond Leading Order

200 papers

Parton shower event generators typically approximate evolution of QCD color so that only contributions that are leading in the limit of an infinite number of colors are retained. Our parton shower generator, Deductor, has used an "LC+"…

High Energy Physics - Phenomenology · Physics 2019-03-27 Zoltan Nagy , Davison E. Soper

We apply Continuous Normalizing Flows trained with the Flow Matching method to the problem of phase-space sampling in Monte Carlo event generation for high-energy collider physics. Focusing on lepton-pair and top quark pair production with…

High Energy Physics - Phenomenology · Physics 2026-04-07 Enrico Bothmann , Timo Janßen , Max Knobbe , Bernhard Schmitzer , Fabian Sinz

A procedure is developed for using Soft Collinear Effective Theory (SCET) to generate fully exclusive events, which can then be compared to data from collider experiments. We show that SCET smoothly interpolates between QCD for hard…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christian W. Bauer , Matthew D. Schwartz

We formulate a collinear partonic shower algorithm that achieves next-to-single-logarithmic (NSL, $\alpha_s^n L^{n-1}$) accuracy for collinear-sensitive non-singlet fragmentation observables. This entails the development of an algorithm for…

High Energy Physics - Phenomenology · Physics 2024-09-16 Melissa van Beekveld , Mrinal Dasgupta , Basem Kamal El-Menoufi , Jack Helliwell , Pier Francesco Monni , Gavin P. Salam

Double parton scattering (DPS) processes in which there is a perturbative $1\to2$ splitting in both protons overlap with loop corrections to single parton scattering (SPS). Any fundamental theoretical treatment of DPS needs to address this…

High Energy Physics - Phenomenology · Physics 2020-10-06 Baptiste Cabouat , Jonathan R. Gaunt

In this work we present a new subtraction method for next-to-leading order calculations that is particularly convenient even when narrow resonances are present. The method is particularly suitable for the implementation of next-to-leading…

High Energy Physics - Phenomenology · Physics 2016-01-27 Tomáš Ježo , Paolo Nason

Transverse-momentum dependent parton distributions can be introduced gauge-invariantly in QCD from high-energy factorization. We discuss Monte Carlo applications of these distributions to parton showers and jet physics, with a view to the…

High Energy Physics - Phenomenology · Physics 2009-02-18 F. Hautmann , H. Jung

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

Next steps in development of the KrkNLO method of implementing NLO QCD corrections to hard processes in parton shower Monte Carlo programs are presented. This new method is a simpler alternative to other well-known approaches, such as…

High Energy Physics - Phenomenology · Physics 2016-08-10 S. Jadach , W. Placzek , S. Sapeta , A. Siodmok , M. Skrzypek

We study contributions from nonperturbative effects and parton showering in NLO event generators, and present applications to jet final states. We find pT-dependent and rapidity-dependent corrections which can affect the shape of observed…

High Energy Physics - Phenomenology · Physics 2013-04-29 S. Dooling , P. Gunnellini , F. Hautmann , H. Jung

In conventional parton showers (including ones based on dipoles/antennae), a given $(\mathrm{Born}+m)$-parton configuration can typically be reached via ${\mathcal O}(m!)$ different "shower histories". In the context of…

High Energy Physics - Phenomenology · Physics 2020-08-26 Helen Brooks , Christian T Preuss , Peter Skands

Several methods to improve the parton-shower description of hard processes by an injection of matrix-element-based information have been presented over the years. In this article we study (re)weighting schemes for the first/hardest…

High Energy Physics - Phenomenology · Physics 2015-05-18 Richard Corke , Torbjörn Sjöstrand

We present a general method to match fully differential next-to-next-to-leading (NNLO) calculations to parton shower programs. We discuss in detail the perturbative accuracy criteria a complete NNLO+PS matching has to satisfy. Our method is…

High Energy Physics - Phenomenology · Physics 2015-06-17 Simone Alioli , Christian W. Bauer , Calvin Berggren , Frank J. Tackmann , Jonathan R. Walsh , Saba Zuberi

In this talk, I show the automated Monte Carlo simulations at next-to-leading order in QCD as well as its matching to parton showers are already feasible within the framework of \MG5aMC. I briefly overview the recent activities and take the…

High Energy Physics - Phenomenology · Physics 2017-08-02 Hua-Sheng Shao

Shower Monte Carlo event generators have played an important role in particle physics. Modern experiments would hardly be possible without them. In this talk I discuss how QCD physics is incorporated into the mathematical structure of these…

High Energy Physics - Phenomenology · Physics 2017-08-23 Zoltan Nagy , Davison E. Soper

This article gives an introduction to transverse momentum dependent (TMD) parton distribution functions and their use in shower Monte Carlo event generators for high-energy hadron collisions, and describes recent progress in the treatment…

High Energy Physics - Phenomenology · Physics 2012-05-30 F. Hautmann , M. Hentschinski , H. Jung

We formulate some first fundamental elements of an approach for assessing the logarithmic accuracy of parton-shower algorithms based on two broad criteria: their ability to reproduce the singularity structure of multi-parton matrix…

High Energy Physics - Phenomenology · Physics 2020-02-27 Mrinal Dasgupta , Frédéric A. Dreyer , Keith Hamilton , Pier Francesco Monni , Gavin P. Salam

We summarise the main features of VINCIA's antenna-based treatment of QCD initial- and final-state showers, which includes iterated tree-level matrix-element corrections and automated evaluations of perturbative shower uncertainties. The…

High Energy Physics - Phenomenology · Physics 2016-09-26 Peter Skands , Nadine Fischer , Stefan Prestel , Mathias Ritzmann

With the use of MARTINI, a model which considers evolving QCD jets against a fluid dynamical background, it is shown that the introduction of formation time to the parton shower after the initial hard scattering is essential for a…

High Energy Physics - Phenomenology · Physics 2024-07-30 Rouzbeh Modarresi-Yazdi , Shuzhe Shi , Charles Gale , Sangyong Jeon

We study the mismatch between a full calculation of non-global single-logarithms in the large-N_c limit and an approximation based on free azimuthal averaging, and the consequent angular-ordered pattern of soft gluon radiation in QCD. We…

High Energy Physics - Phenomenology · Physics 2010-10-27 Andrea Banfi , Gennaro Corcella , Mrinal Dasgupta