Very Low Energy Muons in ATLAS TileCal

A study of the behaviour of very low energy muons in ATLAS TileCal has been made, with data from the stand-alone testbeam of August 2003. Transversal pion beams (\theta = 90\degr) with energies 9, 5 and 3 GeV were targeted at TileRow 2 (A-cells). The low energy muons that reached TileCal were pion decay products, both from pions that decayed before momentum selection (thus having the same energy as the pions) and from pions that decayed between momentum selection and TileCal impact (thus having energies from a continuous spectrum, ranging from 57\% of the pion energy to the nominal beam energy). The conclusions of the study are that muons can be separated from pions for these energies and that GEANT4 simulations describe data correctly.