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Time resolution in TileCal. Petr Tas Charles University in Prague, Institute of Particle and Nuclear Physics. WDS June 8 2005. Introduction. Atlas Hadron Calorimeter Module. Introduction. Test beam Cell map. Energy reconstruction. 25 ns digitizer Gain low - high Flat Filter
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Time resolution in TileCal Petr Tas Charles University in Prague, Institute of Particle and Nuclear Physics WDS June 8 2005
Introduction • Atlas • Hadron Calorimeter • Module
Introduction • Test beam • Cell map
Energy reconstruction • 25 ns digitizer • Gain low - high • Flat Filter • Fit Method
Time resolution • (Todd+Teven)/2 • (Todd-Teven)/2 • Sigma ~ proportion of precision
Time resolution dT ~ sigma(Cell A-1) • Gain cut • Select En interval • (Tod-Tev )/2 distribution • Gaussian fit • Sigma ~ dT • dT vs En
Fit Function • sqrt((P1/sqrt(En))2 + (P2/En)2) • P1 energy term ~ same for calorimerer • P2 noise term ~ low gain x high gain
Fit dT vs En, cell A-1, PMT 2+5, 50 GeV electrons • High gain P1=1.91 ± 0.02 P2=0.21 ± 0.33 • Low gain P1=2.24 ± 0.24 P2=21.1 ± 1.0
Fit dT vs En180 GeV electrons, cell A-1 • High gain P1=2.06 ± 0.03 P2=0.41 ± 0.19 • Low gain P1=2.54 ± 0.04 P2=21.1 ± 0.5
Pions 180 GeVcell A-1 and A-9 l A-1 p A-9
Corrections • (Tod-Tev) /2 and (Tod+Tev)/2
Summary • Fit method – better resolution • Time resolution ~ 0.2 - 0.4 ns