Related papers: Introduction to parton-shower event generators
In this contribution, we will give a brief overview of the progress that has been achieved in the field of combining matrix elements and parton showers. We exemplify this by focusing on the case of electron--positron collisions and by…
We discuss issues of QCD at the LHC including parton distributions, Monte Carlo event generators, the available next-to-leading order calculations, resummation, photon production, small x physics, double parton scattering, and backgrounds…
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…
Cross sections for physical processes that involve very different momentum scales in the same process will involve large logarithms of the ratio of the momentum scales when calculated in perturbation theory. One goal of calculations using…
This talk discusses basic aspects of forward production of jets in pp collisions at high energy, including i) issues on QCD factorization for hard processes at large rapidities, and ii) the role of forward jet measurements at the LHC to…
The most commonly employed formalisms of radiative energy loss have been derived in the high- energy approximation. In its present form, it is reliable only for the medium modifications of inclusive particle spectra. Modifications to this…
In this article we will discuss the basic calculational concepts to simulate particle physics events at high energy colliders. We will mainly focus on the physics in hadron colliders and particularly on the simulation of the perturbative…
A method is detailed for the phase space integration of multi-jets cross sections at lepton colliders, applicable to parton level Monte Carlo's at any order in perturbation theory. Other non-jet objects, massless or massive, can be included…
A next step in development of the KrkNLO method of including complete NLO QCD corrections to hard processes in a LO parton-shower Monte Carlo (PSMC) is presented. It consists of generalisation of the method, previously used for the…
A new version of the Monte Carlo event generator DPMJET is presented. It is a code system based on the Dual Parton Model and unifies all features of the DTUNUC-2, DPMJET-II and PHOJET 1.12 event generators. DPMJET-III allows the simulation…
We study contributions from nonperturbative effects and parton showering in NLO event generators, and present applications to jet final states. We find pT-dependent and rapidity-dependent corrections which can affect the shape of observed…
We investigate parton-branching methods based on transverse-momentum dependent (TMD) parton distributions and matrix elements for the Monte Carlo simulation of multi-particle final states at high-energy colliders. We observe that recently…
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…
Coherent QCD radiation in the hadroproduction of top quark pairs leads to a forward--backward asymmetry that grows more negative with increasing transverse momentum of the pair. This feature is present in Monte Carlo event generators with…
We extend the previously developed small $x$ parton shower algorithm to include the kinematic constraint effect and $k_t$ resummation effect. This work enables the Monte Carlo generator to simultaneously resum large $k_t$ and small $x$…
We propose a sophisticated framework for high-energy hadronic collisions, wherein different QCD physics processes are interleaved in a common sequence of falling transverse-momentum values. Thereby phase-space competition is introduced…
With Run-II of the LHC starting its final year of data-taking, high precision theoretical predictions through Monte-Carlo event generators whose uncertainties match that of the recorded data are of highest importance. This talk summarises…
We provide a pedagogical introduction to the physics of hadronic jets and event shapes at electron-positron colliders. We present some of the main jet definitions and event shape observables studied at lepton colliders and discuss how to…
We report on the development of a new model for the underlying event in hadron-hadron collisions. The model includes parton showers for all interactions, as well as non-trivial flavour, momentum, and colour correlations between interaction…
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…