The MC@NLO 4.0 Event Generator

TL;DR

The paper presents MC@NLO 4.0, a practical event generator that integrates NLO QCD calculations with parton showers for various particle production processes, enhancing simulation accuracy.

Contribution

It introduces MC@NLO 4.0, implementing NLO QCD matrix elements into HERWIG and Herwig++ for a wide range of processes, with improved features over previous versions.

Findings

Supports multiple particle production processes including Higgs and vector bosons.

Includes spin correlations for most processes, enhancing simulation realism.

Provides a comprehensive manual detailing implementation and differences from earlier versions.

Abstract

This is the user's manual of MC@NLO 4.0. This package is a practical implementation, based upon the Fortran HERWIG and Herwig++ event generators, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix elements consistently into a parton shower framework. Processes available in this version include the hadroproduction of single vector and Higgs bosons, vector boson pairs, heavy quark pairs, single top, single top in association with a W, single top in association with a charged Higgs in type I or II 2HDM models, lepton pairs, and Higgs bosons in association with a W or Z. Spin correlations are included for all processes except ZZ production. This document is self-contained, but we emphasise the main differences with respect to previous versions.