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Related papers: QCD (&) Event Generators

200 papers

We make a thorough comparison between different schemes of merging fixed-order tree-level matrix element generators with parton-shower models. We use the most basic benchmark of the O(alpha_S) correction to e+e- -> jets, where the simple…

High Energy Physics - Phenomenology · Physics 2009-04-30 Nils Lavesson , Leif Lonnblad

We introduce the Alaric parton shower for simulating QCD radiation at hadron colliders and present numerical results from an implementation in the event generator Sherpa. Alaric provides a consistent framework to quantify certain systematic…

High Energy Physics - Phenomenology · Physics 2024-04-23 Stefan Höche , Frank Krauss , Daniel Reichelt

This is the user's manual of MC@NLO 2.3. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix elements consistently into a parton shower…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Frixione , B. R. Webber

We consider the production of a Z boson decaying to leptons in association with a bottom-quark pair in hadronic collisions. For the first time, we compute predictions at next-to-next-to-leading order (NNLO) in QCD, and we combine them with…

High Energy Physics - Phenomenology · Physics 2024-06-21 Javier Mazzitelli , Vasily Sotnikov , Marius Wiesemann

At the LHC all processes are QCD ones, whether "signal" or "background". In this review the frontiers of current QCD research are addressed, towards increased understanding, improved calculational precision, and role in potential future…

High Energy Physics - Phenomenology · Physics 2015-06-17 T. Sjöstrand

A new release of the Monte Carlo event generator Herwig (version 7.1) is now available. This version introduces a number of improvements, notably: multi-jet merging with the dipole shower at LO and NLO QCD; a new model for soft interactions…

We give an overview of the status of theoretical predictions for single-top production in the Standard Model. We focus in particular on recent developments, including calculations of off-shell effects at next-to-leading order beyond the…

High Energy Physics - Phenomenology · Physics 2015-06-15 Pietro Falgari

We present a new implementation of photoproduction processes in e+e- and ep collisions into Pythia 8 Monte-Carlo event-generator. In particular we discuss how the parton showers and multiparton interactions are generated with a resolved…

High Energy Physics - Phenomenology · Physics 2017-09-01 Ilkka Helenius

We specify recursive equations that could be used to generate a lowest order parton shower for hard scattering in hadron-hadron collisions. The formalism is based on the factorization soft and collinear interactions from relatively harder…

High Energy Physics - Phenomenology · Physics 2009-04-22 Zoltan Nagy , Davison E. Soper

Results from the new Monte Carlo event generator Herwig++ are presented. This first version simulates Hadron Emission Reactions With Interfering Gluons in electron-positron annihilation. The parton shower evolution is carried out using new…

High Energy Physics - Phenomenology · Physics 2009-11-10 Stefan Gieseke , Alberto Ribon , Michael H Seymour , Philip Stephens , Bryan Webber

High-quality simulated data is crucial for particle physics discoveries. Therefore, parton shower algorithms are a major building block of the data synthesis in event generator programs. However, the core algorithms used to generate parton…

High Energy Physics - Phenomenology · Physics 2022-11-09 Gösta Gustafson , Stefan Prestel , Michael Spannowsky , Simon Williams

We report on a new formalism for parton showers whose fixed-order expansion can be corrected through next-to-next-to-leading order (NNLO) in QCD. It is the first such formalism we are aware of that has no dependence on any auxiliary scales…

High Energy Physics - Phenomenology · Physics 2023-10-31 Peter Skands , Christian T. Preuss

We report on our exploration of matching matrix element calculations with the parton-shower models contained in the event generators HERWIG and Pythia. We describe results for e+e- collisions and for the hadroproduction of W bosons and…

High Energy Physics - Phenomenology · Physics 2011-05-05 Stephen Mrenna , Peter Richardson

Parton showers are accurate for soft and/or collinear emission, but for a good description of the whole of phase space they need to be supplemented by matrix element corrections. In this paper, we discuss matrix element corrections to the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Gennaro Corcella , Michael H. Seymour

We present a consistent way of combining associated weak boson radiation in hard dijet events with hard QCD radiation in Drell-Yan-like scatterings. This integrates multiple tree-level calculations with vastly different cross sections, QCD-…

High Energy Physics - Phenomenology · Physics 2016-02-17 Jesper Roy Christiansen , Stefan Prestel

We present a novel event generation framework for the efficient simulation of vector boson plus multi-jet backgrounds at the high-luminosity LHC and at possible future hadron colliders. MPI parallelization of parton-level and particle-level…

High Energy Physics - Phenomenology · Physics 2019-07-31 Stefan Höche , Stefan Prestel , Holger Schulz

We present the implementation and validation of the techniques used to efficiently evaluate parametric and perturbative theoretical uncertainties in matrix-element plus parton-shower simulations within the Sherpa event-generator framework.…

High Energy Physics - Phenomenology · Physics 2016-11-11 Enrico Bothmann , Marek Schönherr , Steffen Schumann

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

We present a Monte-Carlo event generator for simulating chargino pair production at the ILC at next-to-leading order in the electroweak couplings. We consider two approaches of including photon radiation. A strict fixed-order approach…

High Energy Physics - Phenomenology · Physics 2007-05-23 Tania Robens