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Related papers: Color matrix element corrections for parton shower…

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We use aMC@NLO to study the production of four charged leptons at the LHC, performing parton showers with both HERWIG and Pythia6. Our underlying matrix element calculation features the full next-to-leading order $O(\alpha_S)$ result and…

High Energy Physics - Phenomenology · Physics 2015-05-30 Rikkert Frederix , Stefano Frixione , Valentin Hirschi , Fabio Maltoni , Roberto Pittau , Paolo Torrielli

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

The new methodology of adding QCD NLO corrections in the initial state Monte Carlo parton shower (hard process part) is presented using process of the heavy boson production at the LHC as an example. Despite the simplified model of the…

High Energy Physics - Phenomenology · Physics 2012-10-31 S. Jadach , A. Kusina , M. Skrzypek , M. Slawinska

We describe the details of the calculation of the full colour NNLO QCD corrections to jet production observables at the LHC with antenna subtraction. All relevant matrix elements for the process $pp \to jj$ at NNLO in full colour are…

High Energy Physics - Phenomenology · Physics 2022-10-26 X. Chen , T. Gehrmann , E. W. N. Glover , J. Mo

We perform a detailed study of NLO parton shower matching uncertainties in Higgs boson pair production through gluon fusion at the LHC based on a generic and process independent implementation of NLO subtraction and parton shower matching…

High Energy Physics - Phenomenology · Physics 2018-04-04 Stephen Jones , Silvan Kuttimalai

In recent times the algorithms for the simulation of hadronic collisions have been subject to two substantial improvements: the inclusion, within parton showering, of exact higher order tree level matrix elements (MEPS) and, separately,…

High Energy Physics - Phenomenology · Physics 2015-03-14 Keith Hamilton , Paolo Nason

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

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

The quenching of jets (and high-pT particle spectra) observed in heavy-ion collisions is interpreted as due to the energy lost by hard partons crossing the Quark Gluon Plasma. Here we review recent efforts to include in its modeling…

High Energy Physics - Phenomenology · Physics 2012-10-02 A. Beraudo

Matched calculations combining perturbative QCD with parton showers are an indispensable tool for LHC physics. Two methods for NLO matching are in widespread use: MC@NLO and POWHEG. We describe an alternative, KrkNLO, reformulated to be…

High Energy Physics - Phenomenology · Physics 2025-02-03 Pratixan Sarmah , Andrzej Siódmok , James Whitehead

We investigate the next-to-leading-colour (NLC) contributions to the colour matrix in the fundamental and the colour-flow decompositions for tree-level processes with all gluons, one quark pair and two quark pairs. By analytical examination…

High Energy Physics - Phenomenology · Physics 2022-01-05 Rikkert Frederix , Timea Vitos

We present the implementation of a fully automated quarkonium parton shower in Herwig 7, based on non-relativistic QCD (NRQCD) factorisation with spin-colour projections. The framework systematically incorporates colour-singlet and…

High Energy Physics - Phenomenology · Physics 2025-08-11 M. R. Masouminia , P. Richardson

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

We improve the theoretical predictions for the production of extra neutral gauge bosons at hadron colliders by implementing the Z' bosons in the MC@NLO generator and by computing their differential and total cross sections in joint p_T and…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. Fuks , M. Klasen , F. Ledroit , Q. Li , J. Morel

We discuss coherent QCD radiation from space-like parton branching and its effects on multi-jet final states at high-energy hadron colliders. Coherence effects for small longitudinal momentum fractions x are not included in the branching…

High Energy Physics - Phenomenology · Physics 2009-11-13 F. Hautmann , H. Jung

We consider $W^\pm Z$ production in hadronic collisions and present high-precision predictions in QCD and electroweak (EW) perturbation theory matched to parton showers. To this end, we match next-to-next-to-leading order QCD corrections to…

High Energy Physics - Phenomenology · Physics 2022-11-30 Jonas M. Lindert , Daniele Lombardi , Marius Wiesemann , Giulia Zanderighi , Silvia Zanoli

The leptonic decays of the heavy gauge bosons W and/or Z provide a clear experimental signature at hadron colliders. The production of accompanying jets is an excellent signal to probe QCD, while also being the main background to many…

High Energy Physics - Phenomenology · Physics 2015-03-18 Flavia A. Dias , Emily Nurse , Gavin Hesketh

We report on the implementation of an interface between the SANC generator framework for Drell-Yan hard processes, which includes next-to-leading order electroweak (NLO EW) corrections, and the Herwig++ and Pythia8 QCD parton shower Monte…

High Energy Physics - Phenomenology · Physics 2015-05-20 P. Richardson , R. R. Sadykov , A. A. Sapronov , M. H. Seymour , P. Z. Skands

We compare fixed order and parton shower matched predictions for the process ${pp\rightarrow \ell^+\nu_{\ell} \ell^-\bar{\nu}_{\ell} \ell^{\pm}{\nu}_{\ell} b\bar{b}+X}$ at NLO in QCD, including the orders $\mathcal{O}(\alpha_s^3\alpha^6)$…

High Energy Physics - Phenomenology · Physics 2022-12-06 Jasmina Nasufi

Herwig 7 is a general-purpose Monte Carlo generator of particle collisions comprising both hard perturbative as well as soft phenomenological physics. Herwig is therefore capable to describe the entire final state of hadronized particles in…

High Energy Physics - Phenomenology · Physics 2020-12-04 Johannes Bellm , Cody B. Duncan , Stefan Gieseke , Miroslav Myska , Andrzej Siodmok