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Related papers: Generalized angular-order parton showers in Herwig…

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We present a fully automated framework based on the FeynRules and MadGraph5 aMC@NLO programs that allows for accurate simulations of supersymmetric QCD processes at the LHC. Starting directly from a model Lagrangian that features squark and…

High Energy Physics - Phenomenology · Physics 2016-02-23 Celine Degrande , Benjamin Fuks , Valentin Hirschi , Josselin Proudom , Hua-Sheng Shao

We present predictions for the production cross section of a Standard Model Higgs boson in association with a top-antitop pair at next-to-leading order accuracy using matrix elements obtained from the HELAC-Oneloop package. The NLO…

High Energy Physics - Phenomenology · Physics 2011-11-10 M. V. Garzelli , A. Kardos , C. G. Papadopoulos , Z. Trocsanyi

We study in this paper the production, in hadronic collisions, of final states with W gauge bosons, heavy quark pairs and n extra jets (with n up to 4). The complete partonic tree-level QCD matrix elements are evaluated using the ALPHA…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michelangelo L. Mangano , Mauro Moretti , Roberto Pittau

A new release of the Monte Carlo event generator Herwig (version 7.2) is now available. This version introduces a number of improvements, notably: improvements to the simulation of multiple-parton interactions, including diffractive…

A generalisation of the narrow-width approximation (NWA) is formulated which allows for a consistent treatment of interference effects between nearly mass-degenerate particles in the factorisation of a more complicated process into…

High Energy Physics - Phenomenology · Physics 2014-11-19 Elina Fuchs , Silja Thewes , Georg Weiglein

A nonuniversal abelian extension $\mathrm{U(1)}_{X}$ free from chiral anomalies is introduced into the Standard Model (SM), in order to evaluate its suitability in addressing the fermion mass hierarchy (FMH) by using seesaw mechanisms…

High Energy Physics - Phenomenology · Physics 2018-08-08 Carlos E. Díaz , S. F Mantilla , R. Martinez

Longitudinal electroweak gauge bosons are the most technically delicate ingredient of electroweak parton showers: in the broken Standard Model, the gauge component of a longitudinal polarisation does not cancel diagram by diagram, but is…

High Energy Physics - Phenomenology · Physics 2026-03-19 M. R. Masouminia , P. Richardson

We investigate the effects of keeping the full color structure for parton emissions in parton showers for both LEP and LHC. This is done within the Herwig 7 dipole shower, and includes gluon emission, gluon splitting, initial state…

High Energy Physics - Phenomenology · Physics 2018-11-14 Simon Plätzer , Malin Sjodahl , Johan Thorén

With the discovery of the Higgs at the LHC, experiments have finally addressed all aspects of the Standard Model (SM). At this stage, it is important to understand which windows for beyond the SM (BSM) physics are still open, and which are…

High Energy Physics - Phenomenology · Physics 2015-06-16 Alex Pomarol , Francesco Riva

Beyond standard model (BSM) particles should be included in effective field theory in order to compute the scattering amplitudes involving these extra particles. We formulate an extension of Higgs effective field theory which contains…

High Energy Physics - Phenomenology · Physics 2021-07-07 Ryo Nagai , Masaharu Tanabashi , Koji Tsumura , Yoshiki Uchida

The measurement of the Higgs boson width is a critical test of the Standard Model, with significant implications for understanding electroweak symmetry breaking. Direct measurements are limited by detector resolution, but it can be measured…

High Energy Physics - Phenomenology · Physics 2025-09-10 Rafael Coelho Lopes de Sá , Martina Javurkova , Matteo Lazzeretti , Raoul Röntsch

We present a new formalism for parton shower simulation of QCD jets, which incorporates the following features: invariance under boosts along jet axes, improved treatment of heavy quark fragmentation, angular-ordered evolution with soft…

High Energy Physics - Phenomenology · Physics 2014-11-17 Stefan Gieseke , Philip Stephens , Bryan Webber

We present an antenna-shower formalism that includes helicity dependence for massless partons. The formalism applies to both traditional (global) showers and to sector-based variants. We combine the shower with VINCIA's multiplicative…

High Energy Physics - Phenomenology · Physics 2013-04-03 Andrew J. Larkoski , Juan J. Lopez-Villarejo , Peter Skands

The event generator based on the higher-twist energy loss formalism -- Modular All Twist Transverse-scattering Elastic-drag and Radiation (MATTER) -- is further developed and coupled to a hydrodynamic model for studying jet modification in…

Nuclear Theory · Physics 2020-02-07 Shanshan Cao , Abhijit Majumder

When the initial state evolution of a parton shower is organized according to the standard "backward evolution'' prescription, ratios of parton distribution functions appear in the splitting probabilities. The shower thus organized evolves…

High Energy Physics - Phenomenology · Physics 2015-06-18 Zoltan Nagy , Davison E. Soper

A general introduction is given in chapter 1. Chapter 2 outlines the main features of the Standard Model (SM) of particle physics and the theoretical motivations for going beyond it. We subsequently provide brief descriptions of a few…

High Energy Physics - Phenomenology · Physics 2011-08-30 Andreas Papaefstathiou

We review the physics basis, main features and use of general-purpose Monte Carlo event generators for the simulation of proton-proton collisions at the Large Hadron Collider. Topics included are: the generation of hard-scattering matrix…

The Standard Model (SM) of particle physics, comprised of the unified electro-weak (EW) and Quantum Chromodynamic (QCD) theories, accurately explains almost all experimental results related to the micro-world, and has made a number of…

High Energy Physics - Phenomenology · Physics 2021-03-01 Shenjian Chen , Stephen Lars Olsen

We discuss extensions the CKKW-L and UMEPS tree-level matrix element and parton shower merging approaches to next-to-leading order accuracy. The generalisation of CKKW-L is based on the NL3 scheme previously developed for e+e-…

High Energy Physics - Phenomenology · Physics 2015-06-12 Leif Lonnblad , Stefan Prestel

Vector boson fusion established itself as a highly reliable channel to probe the Higgs boson and an avenue to uncover new physics at the Large Hadron Collider. This channel provides the most stringent bound on Higgs' invisible decay…

High Energy Physics - Phenomenology · Physics 2022-06-29 Partha Konar , Vishal S. Ngairangbam