The ATLAS Muon Trigger

Events containing muons in the final state are important for many physics analyses in the ATLAS experiment at the Large Hadron Collider. To collect such events, an efficient and well-understood muon trigger is required. The ATLAS muon trigger consists of a hardware-based and a software-based subsystems. In order to cope with high luminosity and pileup conditions in Run 2, several improvements have been implemented to suppress the trigger rate while maintaining a high efficiency. The recent improvements include an addition of layers in the coincidence of the muon spectrometer and optimisation of muon isolation. We present an overview of the algorithm improvements of the ATLAS muon trigger and its performances in 2018 data taking.