Development of a Fast Simulation of the LHCb Calorimeter

LHCb is one of the experiments collecting data at the Large Hadron Collider (LHC), and it is the only one specifically designed to perform measurements in the bottom and charm quark sector. Most of the results obtained by LHCb in these sectors during the first two runs of the LHC are the best currently available, and much larger data samples are expected from upcoming runs. During LHC Run 2, the production of simulated events has taken about 80% of the computing resources of the LHCb experiment. Despite this large amount of allocated resources, for some measurements the number of events that was possible to simulate has not been sufficient to make the systematic uncertainty associated to Monte Carlo statistics small compared to the main systematic uncertainties. This thesis presents the first effort towards the development of a fast simulation interface for the LHCb simulation software. It has been designed to be flexible enough to allow the users to choose for which subdetector, and for which particles, the fast simulation should replace the standard simulation. Furthermore, for a given subdetector it allows to activate different fast simulation engines depending on the particle properties. In addition, I developed two hit engines which generate signals for simulated photons passing through the LHCb calorimeter. The performances of these engines have been tested with appropriate simulations and compared to the standard simulation and real data.