LCG Monte-Carlo Events Data Base - LCG MCDB


The adoption of a central database of MC events is motivated by simulation needs which are specific to the high energy physics domain. In general, the correct MC simulation of complex processes requires a rather sophisticated expertise. Often, different physics groups in various experimental collaborations approach the same experts and authors of MC generators, respectively, in order to generate MC samples for a particular physics process. Having these events stored in a public place along with the corresponding documentation, allows for direct cross checks of the performances on reference samples, and prevents possible waste of precious human and computing resources. At the Les Houches workshop at 2003 new proposal for LCG MCDB project has been presented. Now the first version of this project is realised and ready for users. The project facilitates communication between Monte-Carlo experts and users of event samples in LHC Collaborations. The previous release of MCDB CMS MCDB) is now operational for the CMS collaboration. The new attractive features of LCG MCDB are presented below as well as the introduction to the project and initial users manual.

Motivation for LCG MCDB

One of the most general problems for the experimental high energy physics community is Monte-Carlo (MC) simulation of physics processes. There are numerous publicly available MC generators. However, the correct MC simulation of complicated processes requires in general rather sophisticated expertise on the part of their users. Often, a physics group in an experimental collaboration requests experts and/or authors of MC generators to create MC samples for a particular process. Furthermore, it is common that the same physics process is investigated by various physics groups in need of the same MC event samples. The main motivation behind the Monte-Carlo Data Base (MCDB) project is to make MC event samples, as prepared by experts, available for various physics groups.

Invitation to use MCDB

We invite authors of MC tools and experts to use new LCG MCDB project:
which is successor of the old CMS version:

The main features of LCG MCDB

  • Powerful WEB interface with Content Management System for the authors of event samples and their users
  • SQL structure of event sample documentation
  • Power SQL/XML based search engine
  • CASTOR as the native storage for the MC samples
  • Direct uploading of multiple files from AFS/CASTOR/GRID to LCG MCDB
  • Direct downloading of files from LCG MCDB with WEB/CASTOR/GRID paths (URI)
  • Flexible and reliable authorization system based on CERN AFS/Kerberos logins or LCG GRID certificates
  • BackUp of samples and SQL information
  • API to collaboration software (in progress)
  • HEPML. Unified events format and automatic parsing of event samples from different MC generators (in progress)

How people can use LCG MCDB

  • Authors of new MC samples can upload the samples to the public MC events Data base (web interface is provided as well as a storage)
  • Authors can document it in the standard and easy way (secure web interface and documentation templates are provided)
  • Authors can publish these events with documentation on the public web site, can unpublished it and edit again.
  • Authors can answer users comments on the particular sample and documentation.
  • Users are interesting in new MC samples, can search the MCDB, read author's documentation and comments on the samples, and download events

Short HOW-TO for new authors of LCG MCDB

If you want to share your new MC sample with other groups, please do the following:
  • Register as a new author at the "Register New Author" at the right side menu of the main LCG MCDB web page, then wait for the confirmation e-mail
  • Login to the LCG MCDB authors area at the "Login" link at the right side menu
  • Choose "Create New Article" at the new right side menu
  • Fill the fields in the documentation templates, which will appear (title, generator, theoretical model, cuts, ...)
  • Upload your event files in the "Event Files" slice
  • Click "Preview/Save" slice and check the box "Publish"
Now, your new article and samples are become publically available in the particular physics category.
Notes: 1. You need valid CERN AFS login to be an authorized author of LCG MCDB (if you have any computer account in CERN you probably have CERN AFS login already); 2. if you do not finished the description of your files in documentation template forms you can come back later and continue; 3. You can publish and unpublish all of your articles in any time; 4. You can edit all of your articles in any time.

Short HOW-TO for the users of LCG MCDB

If you are looking for some MC sample:
  • please check the appropriate categories at the left side menu of the main LCG MCDB page or search the entire database (the search form on the same page)
  • If you have found the appropriate MC sample you can check the authors documentation on this sample and download events directly from the web page
  • If you want to ask author of this sample or share some comment on this sample, please, use "View/post comments on article" interface which is available for the particular article
  • If you want to post some comments on the LCG MCDB project itself, please, use "Feedback comments" interface, which is available at the right side menu of the main LCG MCDB web page

Wiki Information:

More information


The description of previous version of MCDB which operates in CMS collaboration - CMS MCDB is available here:
hep-ph/0404241 (HTML version)


Initial description of LCG MCDB is available here:
hep-ph/0403100 (HTML version)

Les Houches proceedings LCG MCDB is available here:
hep-ph/0604120 (pages 200-204)

Most recent publication on LCG MCDB is available here:
hep-ph/0703287 (HTML version)