Simulation in LHCb

This page is intended to hold fast evolving information on the simulation and to allow contributions by all. More information is available from the Gauss official web site that is cross referenced to this site.

Some topics in these pages may be not up to date, in which case they are indicated with (May-Be-)Not-Up-To-Date. If you find something is no longer up to date, please tag it as such.

Topic being worked on are indicated with In-Work.

Conveners: Adam Davis, Michal Kreps

Introduction

Gauss is the LHCb Simulation software, built on the Gaudi Framework.
It consist of a first phase where the events are generated (e.g. pp collisions at 14 TeV) and a second phase where the particles are propagated trough the LHCb detectors.

Current production version is Sim09. For differences in Sim09 versions, please go to Sim09Differences

Coordinators

The Gauss integration and release manager is Gloria Corti. The list of topics and coordinators/contacts is here.

Gauss Web

The main Gauss web page containing release information and links to user guides and tutorials, is here.

Gitlab Repositories

The LHCb simulation framework is housed in the following Gitlab repositories:

• Gauss
• DecFiles
• Boole

Nightly Tests, Performance Regression and Tools

Nightly tests can be found here.

LHCbPR is found here.

Generator Statistics for Sim09 can be found here.

Documentation

• Gauss FAQ
• Gauss and DecFiles Tutorials for self-teaching
• Information on Generators in Gauss, In-WorkA collection of information related to the generator part of Gauss: links, talks, notes. More information available from the Gauss web page.
• Information on Detector simulation (Gauss and Boole), May-Be-Not-Up-To-Date A collection of notes, talks and links related to the description of the status of the simulation and digitization for the different subdetectors.
• Simulation Conditions used in productions and for which data are available with some explanation In-Work
• Meetings, Presentation and Workshops
• Publications
• Guide for producing statistics tables. For Sim08 production you might also want to consult this older guide.
• Information on the filtered simulation productions
• Unofficial tool for finding the event type of a decay
• How to code efficient dec-files with Tight-cuts?
• How to code efficient dec-files with a cut on decay dependent variables, such as visible mass?
• Information on ReDecay
• Differences between Sim09 versions

Current and future developments

• Simulation Draft Board for development contributions. Recipes, scripts and code to share. This may be make available to be centrally release once tested.
• Simulation Validation (and tuning). List of samples for validation, reference distributions from Physics Working Group, tools to help in validation. A dedicated page for an alternative method of event generator validation and tuning using the RIVET/Professor system is available here.
• List of Simulation Tasks, the evolution of some of those being worked on can be followed on the Savannah task list (Simulation category). The old list on twiki is being migrated there. Detailed descriptions and documentation for specific topics are linked from the savannah task and are also linked from the old list on twiki that will become just a list of supporting documentation.
• Simulation for Upgrade
• Status for Sim08
• Generators in Gauss: Pythia8, Herwig++, EvtGen, Sherpa

Bugs and features

To report new bugs or unexpected feature use the LHCbGAUSS JIRA.

You can also check the list of already known bugs and their status.

MC Liaisons

A list of all current MC Liaisons can be found at LHCbWGLiaisons

MC Piquet

A report on the status of the MC Requestsis presented every two weeks at the PPTS meeting. Instructions for those preparing the report can be found here.

Future releases

The current sets are under active development and support:

Deadline for contributions	Project/Package	Version	Details	Group	Release
20 Jan 2013 -	DecFiles	v25r22	Definition of new event types for MC11a	MC11a	21 Jan 2013
20 Jan 2013 -	DecFiles	v26r22	Definition of new event types for MC-2012	2012	21 Jan 2013
27 Jan 2013	DecFiles	v27r1	With new DECAY.DEC for final tests with Gauss >= v44r2	2012	28 Jan 2013
18 Jan 2013 -	Gauss	v42r4	All new code for LHCb as reference - no new generators nor G4	DEV	21 Jan 2013
18 Jan 2013 -	Gauss	v43r4	For tests with Geant4 v95r1 and new version of pythia6, lhapdf, based on LHCb v35r3/Gaudi v23r3,	DEV	21 Jan 2013
22 Jan 2013 -	Gauss	v44r4	For tests with new EvtGen v13r1 with interface to tauola++, photos++ and pythia8	DEV	23 Jan 2013
25 Jan 2013 -	Geant4	v95r2p1	Build of G4 9.5.p02 with G4 examples	2012	28 Jan 2012
22 Jan 2013 -	Geant4	v95r2	Build of G4 9.5.p02 with Voxel volumes from 9.6	DEV	10 Feb 2013
28 Jan 2013	Gauss	v45r0	First version with all new features for production for physics with 2012 data	2012	31 Jan 2013
25 Jan 2013 -	Boole	v26r2	Based on LHCb v35r3 or v35r4/Gaudi v23r4, with support for upgrade and for productions for 2012	2012	28 Jan 2013

See the LHCb Tag Collector for details, status and deadline for contributions for future versions.

Instructions to Gauss Managers to prepare releases

• Geant4 releases
• Gauss releases
• DecFiles releases

Fast Simulations

• DelphesFastSimulation