The Level-0 calorimetric trigger of the NA62 experiment

The NA62 experiment at the CERN SPS aims at measuring the branching ratio of the very rare kaon decay K+ → π+ ν bar nu (expected 10−10) with a 10% background. Since an high-intensity kaon beam is required to collect enough statistics, the Level-0 trigger plays a fundamental role in both the background rejection and in the particle identification. The calorimetric trigger collects data from various calorimeters and it is able to identify clusters of energy deposit and determine their position, fine-time and energy. This paper describes the complete hardware commisioning and the setup of the trigger for the 2015 physics data taking.