ATLAS Global Tau Trigger Performance Study for Run 4

Tau decays are notoriously difficult to detect because many particles decay with a similar signature. The upgrade of the ATLAS Trigger and Data Acquisition system for the High-Luminosity Large Hadron Collider will provide high-granularity calorimeter information, offering enhanced performance required for operation during Run 4 (with 200 interactions per bunch crossing). Here we present the expected tau trigger performance, including the efficiency and background rejection.