Implementation of an online algorithm to calculate Inner Detector Trigger tracking efficiencies using Tag and Probe analysis

Inner detector (ID) tracking is a very important prerequisite in the correct triggering of many important signatures. Evaluating its efficiency is a fundamental task, as it ensures that the data collected by the trigger system will be relevant and sufficient for future analysis. Until now the ATLAS efficiency monitoring has been carried out in the Tier 0 processing, which means that there was a delay between the retrieval of the data and the feedback on the data quality. The goal of the work project described in this report was to implement a monitoring algorithm which evaluates the efficiency of the ID trigger tracking in the real time, which would enable the ATLAS trigger system to have an instantaneous feedback of the performance of the ID trigger tracking. This would be also useful for monitoring possible irregularities within the detector, which could be inferred from a sudden change in the efficiency plots. The algorithm has been named TrigIDTPMonitor, it uses tag and probe analysis and its implementation allows monitoring of several reconstruction algorithms at the same time.