This tutorial teaches you the basics of the Herwig 7 Monte Carlo Event Generator. An installation of Herwig on your own device is not necessary if you use the provided Docker image (see below). If you plan to use Herwig for your own research, please follow the instructions provided under Installation for a local build.

For the purpose of this tutorial, you do not need to install Herwig.

In this tutorial, you will learn:

• How to simulate generic LHC Events;
• How to combine Herwig with NLO Tools like MadGraph and OpenLoops;
• How to include rivet analyses and compare a simulation with data;
• How to switch parts of the Event Generator on and off;
• How to modify parameters of the Parton shower and the Hadronisation model;
• How to run LHE files in Herwig with its Les Houches Event Handler.

Before you start: setting up Herwig's docker containers

All exercises within this tutorial can be done by using the provided Docker image for Herwig. This contains a working copy of Herwig's latest version, Herwig-7.3.0, with ThePEG-2.3.0. If you have not already installed Docker, please follow the instructions on the Docker website and install Docker on your device.

The required Docker containers can be pulled directly from the Docker Hub with

docker pull herwigcollaboration/herwig-7.3:7.3.0

Linux users will need to add sudo to the beginning of the above command.

In order to run Herwig, execute the following shell command,

docker run -i --rm -u `id -u $USER`:`id -g` -v $PWD:$PWD -w $PWD herwigcollaboration/herwig-7.3:7.3.0 Herwig --help

This allows the container to access your local files and to write to the current working directory.

Create an alias for the run command by editing the file ~/.bashrc on your local machine. Simply add the following line to the end of .bashrc

alias DRH='docker run -i --rm -u `id -u $USER`:`id -g` -v $PWD:$PWD -w $PWD herwigcollaboration/herwig-7.3:7.3.0'

To run Herwig execute

DRH Herwig

Similar commands like rivet-mkhtml can be run in the same fashion

DRH rivet-mkhtml

From here on, we will use the alias DRH to denote running Herwig-7.3.0 from its Docker image.

If this works, you are ready to start the tutorial with First run. If you encounter problems, please talk to a tutor.

Instructions:

1. Installation
2. First run: Z production at the LHC
3. Second run: NLO Z production at the LHC
4. Third run: minimum bias events and soft physics
5. The Les Houches Event Handler
6. Photon Induced Process in Herwig

Helpful literature
Herwig manual