1. Time resolution in TileCal
Petr Tas
Charles University in Prague,
Institute of Particle and Nuclear Physics
WDS June

2. Introduction
Atlas
Hadron Calorimeter
Module

3. Introduction
Test beam
Cell map

5. Energy reconstruction
25 ns digitizer
Gain low - high
Flat Filter
Fit Method

6. Time resolution (Todd+Teven)/2 (Todd-Teven)/2
Sigma ~ proportion of precision

7. Time resolution dT ~ sigma (Cell A-1)
Gain cut
Select En interval
(Tod-Tev )/2 distribution
Gaussian fit
Sigma ~ dT
dT vs En

8. Flat filter p vs Fit method l

9. Fit Function sqrt((P1/sqrt(En))2 + (P2/En)2)
P1 energy term ~ same for calorimerer
P2 noise term ~ low gain x high gain

10. 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

11. Fit dT vs En 180 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

12. Pions 180 GeV cell A-1 and A-9
l A-1
p A-9

13. Corrections
(Tod-Tev) /2 and (Tod+Tev)/2

14. Summary
Fit method – better resolution
Time resolution ~ ns