Use of Hadronic Calorimetry Information in the ATLAS Level-1 Muon Trigger

The ATLAS Tile hadronic calorimeter (TileCal) provides highly-segmented energy measurements for incident particles. Information from TileCal´s last radial layer can assist in muon tagging and has been considered for inclusion in an upgraded Level-1 trigger. It can assist in the rejection of fake muon triggers arising from background radiation without degrading the efficiency of the trigger. This paper addresses the additional muon discrimination obtained by using a new receiver for the TileCal signals which interfaces with the current ATLAS Level-1 muon trigger. The design and performance of the receiver are also described.