Implementation and performance of the ATLAS Trigger Muon "Vertical Slice"

The ATLAS experiment at the Large Hadron Collider has a tigger system designed to keep high effiency for interesting events while achieving a rejection of low transverse momentum physics of about 10^7, thus reaching the ¬200 events/s storage capability of the Data Aquisition system. A three-levels structure has been implemented for this purpose, as described in this work for the case of the muon trigger system. After describing the implementation, some performance results are presented in term of final trigger rates, resolutions, efficiencies, background rejection and algorithm latency.