Trigger of low pT muons with the ATLAS hadronic calorimeter

A strategy for tagging muons with the Tile Calorimeter at the second level trigger (LVL2) of the ATLAS experiment is presented and its efficiency and mistagging fraction are discussed. It is demonstrated that the Tile Calorimeter can identify muons with good efficiency down to pT=2 GeV/c where the stand-alone muon spectrometer has zero efficiency. A method of exploiting all information available at LVL2 to reduce spurious muon-tag and measure the candidate muon momentum is discussed. The effectiveness of this method is tested, in particular, in the case of bb̄ events at low Large Hadron Collider luminosity (1033 cm−1 s−2) with full simulation of experimental conditions.