The CMS Level-1 Tau identification algorithm for the LHC Run II

AbstractThe CMS experiment implements a sophisticated two-level online selection system that achieves a rejection factor of nearly 105. The first level (L1) is based on coarse information coming from the calorimeters and the muon detectors while the High Level Trigger combines fine-grain information from all sub-detectors. To guarantee a successful and ambitious physics program despite the very large backgrounds and proton-proton collision rates, the CMS Trigger and Data acquisition system must be consolidated. In particular the L1 Calorimeter Trigger hardware and architecture will be upgraded, benefiting from the recent microTCA technology allowing the calorimeter granularity to be better exploited in more advanced algorithms. Benefiting from the enhanced granularity provided by the new system, an innovative dynamic clustering technique has been developed to obtain an optimized tau selection algorithm