Delphes MC Production

This twiki describes the process used to generate Delphes parameterized MC samples for Snowmass and ECFA. For further reference, see arXiv:1309.1057, arXiv:1308.1636, and arXiv:1308.0843.

Collaborators: Jacob Anderson, Aram Avetisyan, Sapta Bhattacharya, Raymond Brock, John Campbell, Sergei Chekanov, Timothy Cohen, Nitish Dhingra, James Dolen, James Hirschauer, Kiel Howe, Ashutosh Kotwal, Tom LeCompte, Sudhir Malik, Patricia Mcbride, Kalanand Mishra, Meenakshi Narain, Jim Olsen, Sanjay Padhi, Michael E. Peskin, John Stupak III, Jay G. Wacker

Overview

Monte Carlo samples for Snowmass and ECFA were produced using opportunistic resources on the OSG, with a production chain consisting of MadGraph -> Bridge -> Pythia -> Delphes.

MadGraph

MadGraph gridpacks were generated for SM backgrounds, binned in generator level S_T. MadGraph was used out-of-the-box without modification.

Bridge

Bridge was used to decay all heavy particles produced by MadGraph. These particles were forced to decay democratically to quarks and leptons to generate enhanced statistics for leptonic final states. In order to reweight the MC samples back to the true branching ratios, the ratio of the true BR to the simulated BR was stored on an event-by-event basis. For many of the larger backgrounds, NLO k-factors are available in the literature. For these backgrounds, the event weight also contained the k-factor.

Pythia

The version of Pythia shipped with MadGraph was used for fragmentation and hadronization, but could not be used out-of-the-box. The event weights calculated during the Bridge processing needed to be passed through the Pythia processing without being overwritten. For this reason, the following modifications were required:

SANJAY

Delphes

A custom version of Delphes was also used. The reason for this was two-fold: to pickup the event weights from Pythia and to include jet substructure techniques. The modifications for the event weights (jet substructure) can be seen in the SANJAY (FastJetFinder) module.

Code

The code used for ECFA can be found here. Bridge, Pythia, and Delphes can be found within the "BRIDGE_MOD", "MG5", and "Delphes-3.0.10" directories, respectively.

The remaining scripts were used to submit/run jobs on OSG-exsede. submitECFAJobs.py is the top level script to submit condor jobs on OSG-xsede. It uses doDelphesECFA.templ.job as a template to form condor job description files, each of which specifies doDelphesECFA.sh as the exectuable.

-- Main.JohnStupak - 15 May 2014