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Related papers: Spin Correlations in Parton Shower Simulations

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In this paper we describe Herwig++ version 2.3, a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron collisions. A number of important hard scattering processes are…

High Energy Physics - Phenomenology · Physics 2009-09-29 M. Bahr , S. Gieseke , M. A. Gigg , D. Grellscheid , K. Hamilton , O. Latunde-Dada , S. Platzer , P. Richardson , M. H. Seymour , A. Sherstnev , J. Tully , B. R. Webber

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

Comparisons of experimental data with theoretical predictions for collider processes containing hadronic jets rely on shower Monte Carlo event generators to include corrections to perturbative calculations from hadronization, parton…

High Energy Physics - Phenomenology · Physics 2013-05-15 S. Dooling , P. Gunnellini , F. Hautmann , H. Jung

Monte Carlo event generators are essential components of almost all experimental analyses and are also widely used by theorists and experiments to make predictions and preparations for future experiments. They are all too often used as…

High Energy Physics - Phenomenology · Physics 2013-04-25 Michael H. Seymour , Marilyn Marx

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

This is the user's manual of MC@NLO 3.4. 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 2008-12-04 Stefano Frixione , Bryan R. Webber

When parton distributions are falling steeply as the momentum fractions of the partons increases, there are effects that occur at each order in $\alpha_s$ that combine to affect hard scattering cross sections and need to be summed. We show…

High Energy Physics - Phenomenology · Physics 2016-11-03 Zoltan Nagy , Davison E. Soper

The leading-order accurate description of top quark pair production, as usually employed in standard Monte Carlo event generators, gives no rise to the generation of a forward--backward asymmetry. Yet, non-negligible -- differential as well…

High Energy Physics - Phenomenology · Physics 2015-06-15 Jan Winter , Peter Z. Skands , Bryan R. Webber

We present a Monte Carlo generator that implements significant theoretical improvements in the simulation of top-quark pair production and decay at the LHC. Spin correlations and off-shell effects in top-decay chains are described in terms…

High Energy Physics - Phenomenology · Physics 2017-02-01 Tomáš Ježo , Jonas M. Lindert , Paolo Nason , Carlo Oleari , Stefano Pozzorini

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

Monte Carlo event generators for hard hadronic collisions depend on the evolution of parton showers backwards from a high-scale subprocess to the hadronization scale. The evolution is treated as a branching process with a sequence of…

High Energy Physics - Phenomenology · Physics 2024-04-16 Stefano Frixione , Bryan R. Webber

We introduce a new model for soft interactions in the Monte Carlo event generator Herwig. We add a new model for the simulation of diffractive final states, based on the cluster hadronization model in Herwig. The soft component of the…

High Energy Physics - Phenomenology · Physics 2017-04-03 S. Gieseke , P. Kirchgaeßer , F. Loshaj

Anomalous contributions to the electric and magnetic dipole moments of the $\tau$ lepton from new physics scenarios have brought renewed interest in the development of new charge-parity violating signatures in $\tau$-pair production at…

High Energy Physics - Phenomenology · Physics 2024-07-19 Sw. Banerjee , A. Yu. Korchin , E. Richter-Was , Z. Was

We present a novel method to combine QCD calculations at next-to-next-to-leading order (NNLO) with parton shower (PS) simulations, that can be applied to the production of heavy systems in hadronic collisions, such as colour singlets or a…

High Energy Physics - Phenomenology · Physics 2022-01-11 Pier Francesco Monni , Paolo Nason , Emanuele Re , Marius Wiesemann , Giulia Zanderighi

This is the user's manual of MC@NLO 3.3. 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 report on the implementation of a coherent dipole shower algorithm along with an automated implementation for dipole subtraction and for performing POWHEG- and MC@NLO-type matching to next-to-leading order (NLO) calculations. Both…

High Energy Physics - Phenomenology · Physics 2015-05-30 Simon Platzer , Stefan Gieseke

If large-angle multigluon radiation contributes significantly to parton showers associated with heavy boson production at the LHC, appropriate parton branching methods are required for realistic Monte Carlo simulations of final states. We…

High Energy Physics - Phenomenology · Physics 2010-06-29 M. Deak , A. Grebenyuk , F. Hautmann , H. Jung , K. Kutak

We present a parton shower which implements the DGLAP evolution of parton densities and fragmentation functions at next-to-leading order precision up to effects stemming from local four-momentum conservation. The Monte-Carlo simulation is…

High Energy Physics - Phenomenology · Physics 2017-11-01 Stefan Höche , Frank Krauss , Stefan Prestel

In these proceedings we present three possible interpretations of the ordering variable implemented in the Herwig7 angular-ordered parton shower. Each interpretation determines a different recoil-scheme prescription and we show how it can…

High Energy Physics - Phenomenology · Physics 2019-12-13 Silvia Ferrario Ravasio , Gavin Bewick

This paper presents the method of combining parton shower formalism with perturbative calculations (matrix elements) in form of a Monte-Carlo algorithm for the process g g -> Z b anti-b,consistenlty including the heavy quark masses and…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. P. Kersevan , I. Hinchliffe , L. Mijovic