Data Driven Approach to Calorimeter Simulation in CMS

CMS is looking forward to tune detector simulation using the forthcoming collision data from the LHC. CMS established a task force in February 2008 in order to understand and reconcile the discrepancies observed between the CMS calorimetry simulation and the test beam data recorded during 2004 and 2006. Within this framework, significant effort has been made to develop a strategy of tuning fast and flexible parameterizations describing showering in the calorimeter with available data from test beams. These parameterizations can be used within the context of Full as well as Fast Simulation. The study is extended to evaluate the use of first LHC collision data, when it becomes available, to rapidly tune the CMS calorimeter.