Speaker
Mike Hildreth
(University of Notre Dame (US))
Description
Within the last year, design studies for LHC detector upgrades have begun to reach a level of detail that requires the simulation of physics processes with simulation performance at the level provided by Geant4. Full detector geometries for potential upgrades have been designed and incorporated into the CMS software. However, the extreme luminosities expected during the lifetimes of the upgrades must also be simulated. The use of many individual minimum-bias interactions to model the pileup poses several challenges to the CMS Simulation framework, including huge memory consumption, increased computation time, and the necessary handling of large numbers of event files during Monte Carlo production.
Recently, CMS has re-engineered the Simulation framework to allow the addition of pileup events using a dramatically smaller memory footprint. An alternate framework has been designed that can take the additional interactions from the data itself, obviating the need for hundreds of simulated minimum bias interactions to populate a single hard-scatter Monte Carlo event. Both of these developments are expected to have a dramatic impact on the efficiency of Monte Carlo production for the upcoming 14 TeV running and future CMS upgrade studies, and both can be used by the CMS Fast Simulation and the Full Geant4-based code. The structure of these reforms and the problems faced in their implementations will be discussed.
Primary author
Mike Hildreth
(University of Notre Dame (US))
