Triggering on hadronic tau decays: ATLAS meets the challenge

Abstract

Hadronic tau decays play a crucial role in taking Standard Model (SM) measurements as well as in the search for physics beyond the SM. However, hadronic tau decays are difficult to identify and trigger on due to their resemblance to QCD jets. Given the large production cross-section of QCD processes, designing and operating a trigger system to efficiently select hadronic tau decays, while maintaining the rate within the bandwidth limits, is a difficult challenge. This contribution will summarize the status and performance of the ATLAS tau trigger system during the 2010–2011 data taking period. Different methods that have been explored to obtain the trigger efficiency curves from data will be shown. Finally, the status of the measurements, which include hadronic tau decays in the final state, will be summarized. In light of the vast statistics collected in 2011, future prospects for triggering on hadronic tau decays in this exciting new period of increased instantaneous luminosity will be presented.