Related papers: Implementing the ME+PS merging algorithm
We propose a novel algorithm, called REGGAE, for the generation of momenta of a given sample of particle masses, evenly distributed in Lorentz invariant phase space and obeying energy and momentum conservation. In comparison to other…
We present an algorithm to evaluate the exact, tree-level matrix elements for multi-parton processes in QCD. We tested this technique, based on the recursive evaluation of the S-matrix, on processes such as gg -> n gluons and q qbar -> n…
PYTHIA is a general-purpose event generator for multiparticle production in high-energy physics. After a general introduction and program news survey, some areas of recent physics progress are considered: the matching to matrix elements,…
The Monte Carlo event generator PHOKHARA, which simulates hadron and muon production at electron-positron colliders through radiative return, has been extended to final states with three pions. A model for the form factor based on…
This publication presents the combination of the one-loop matrix-element generator Recola with the multipurpose Monte Carlo program Sherpa. Since both programs are highly automated, the resulting Sherpa+Recola framework allows for the…
We discuss the necessary steps for implementing an angularly ordered (AO) electroweak (EW) parton shower in Herwig 7 multi-purpose event generator. This includes calculating the helicity-dependent quasi-collinear EW branching functions that…
The Matrix Element Method (MEM) has proven beneficial to make maximal use of the information available in experimental data. However, so far it has mostly been used in Born approximation only. In this paper we discuss an extension to NLO…
We evaluate the theoretical uncertainties in next-to-leading order plus parton shower predictions for top quark pair production and decay in hadronic collisions. Our work is carried out using the Herwig 7 event generator and presents an…
We study the use of cell resampling to reduce the fraction of negatively weighted Monte Carlo events in a generated sample typical of that used in experimental analyses. To this end, we apply the Cell Resampler to a set of $pp \rightarrow…
We have developed an extended framework, named GR@PPA, of the GRACE system for hadron collisions. The GRACE system is an automatic Feynman diagram calculation system and an event generator based on this diagram calculation. While the…
By decoupling the geometric from the dynamical contributions in the scattering processes, we develop a method to compute the scattering matrix of electrons in a one-dimensional coherent conductor connected to two electrodes. In particular,…
This paper presents a new event generator, ALPGEN, dedicated to the study of multiparton hard processes in hadronic collisions. The code performs, at the leading order in QCD and EW interactions, the calculation of the exact matrix elements…
We study various conceivable photoproduction reactions in a polarized ep collider mode of HERA with respect to their sensitivity to the proton's polarized gluon distribution. A special emphasis is put on the `resolved' part of the cross…
We present a fully automated framework as part of the Sherpa event generator for the computation of tree-level cross sections in beyond Standard Model scenarios, making use of model information given in the Universal FeynRules Output…
We give a report of medium modification of Z+jet correlations in Pb+Pb collisions at the Large Hadron Collider using Sherpa to generate initial Z+jet at next-leading-order matrix element matched parton shower, and the Linear Boltzmann…
We consider $ZZ$ production in hadronic collisions and present state-of-the-art predictions in QCD perturbation theory matched to parton showers. Next-to-next-to-leading order corrections to the quark-initiated channel are combined with…
This document describes the novel techniques used to simulate the common Snowmass 2013 Energy Frontier Standard Model backgrounds for future hadron colliders. The purpose of many Energy Frontier studies is to explore the reach of high…
The shapes of invariant differential cross section for charged hadron production as function of hadron's transverse momentum and rapidity in ep collisions at HERA machine are considered. The particle spectra shapes observed in pp and…
The aim of this work is to describe in detail the POWHEG method, first suggested by one of the authors, for interfacing parton-shower generators with NLO QCD computations. We describe the method in its full generality, and then specify its…
This is the user's manual of MC@NLO 2.0. 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…