Triggering on hadronic tau decays in ATLAS: semiconductor tracking detectors in action

Hadronic tau decays play a crucial role in taking Standard Model measurements as well as in the search for physics beyond the Standard Model. 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 with the capability 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 2011 data taking period, emphasizing the key role of semiconductor tracking detectors for tracking and vertexing. Different methods that have been explored to obtain the trigger efficiency curves from data will be shown. Finally, 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.