Time resolution of the Atlas Tile calorimeter and its performance for a measurement of heavy stable particles

Time resolution of the Atlas Tile calorimeter modules has been measured using the test beam data. The resolution depends on an energy deposited in a given cell and is equal to about 1.5 $ns$ at $E$ = 1 $GeV$, 270 $ps$ at $E$ = 25 $GeV$ (high gain), 700 $ps$ at $E$ = 25 $GeV$ (low gain) and 170 $ps$ at $E$ = 150 $GeV$. These values have to be compared to the time of flight of relativistic particles to reach first samples of Tile calorimeter (from 8.3 $ns$ to 20 $ns$). Time of Flight measurement using Tile Calorimeter can be used to identify, and combined with momentum measurements by Atlas inner detector, to measure the mass of exotic heavy stable particles. The results are compared to previous analysis using the Atlas muon spectrometercite{KRAAN2}.