Energy scale calibration in MCEnergy scale calibration in MC(update)(update)

P.Gauzzi

ProblemsProblems

• central modules (1, 2, 17, 18)• long modules (3—12, 19—28)• short modules (13—16, 29—32)

• Overall 1.5% miscalibration in the energy scale

• Endcaps: three different behaviours: for central modules Eclust > Ekine

for the other ones Eclust < Ekine

• Holes in the regions between the long and short modules(x = ±163cm)

• Y-behaviour of long mod. due to extra attenuation factor in CLUADJUST function (Matteo & Stefano)

• EC A• EC B

Old MCOld MC

Old MCOld MCNEW MC OLD MC

offset(MeV) slope offset(MeV) slope

Barrel -2.84±0.03 0.9868±0.0002 -2.88±0.06 1.0060±0.0003EC-Central -2.25±0.09 1.0500±0.0005 -2.0 ± 0.3 1.057 ± 0.001EC-Long -3.31±0.04 0.9817±0.0002 -2.9 ± 0.1 1.0000±0.0005EC-Short -4.3±0.2 0.935±0.001 -3.2 ± 0.4 0.966 ± 0.003

• Almost the same offsets• Barrel and EC-Long modules had slope = 1• EC-Central and EC-Short modules have the same slope

Old MCOld MC• EC A• EC B

• central mod. (1, 2, 17, 18)• long mod. (3—12, 19—28)• short mod. (13—16, 29—32)

•The same three kinds of response

• The same holes at ± 163 cm

• Response was not decreasing with X

• No Y-dependence

Three different responsesThree different responses• In the event generation and in the calorimeter reconstruction have been used different attenuation lengths

PMT from distance d

e A)(1 eA curve Att. 21 λ

d

λ

d

Generation Reconstruction A 1(cm) 2(cm) A 1(cm) 2(cm) Barrel+EC-Long 0.35 50 430 (pl.1, 2) 0.35 50 430 (pl.1, 2) 380 (pl.3) 380 (pl.3) 330 (pl.4,5) 330 (pl.4,5)EC_Central 0.35 50 430 (pl.1, 2) 0.35 50 330(all planes) 380 (pl.3) 330 (pl.4,5)EC 13, 29 0.35 50 330(all planes) 0.35 50 430 (pl.1, 2) 380 (pl.3) 330 (pl.4,5)EC other short mod. 0.35 50 330(all planes) 0.35 50 330(all planes)

Different Different 22

d (cm)

(a.u.) •For EC-Central we use the red curve in generation and the blue one in reconstruction the response is overestimated

• For EC mod. 13 and 29 is the opposite: the response is underestimated the effect “short modules” is mainly due to mod. 13 and 29 that dominate the sample the holes at ± 163 cm are not holes; X= ± 163 cm is the position of the mod. 13 and 29

Y-dependenceY-dependence• Y-dependence of blue points due to the extra correction implemented in CLUADJUST

0.98 e e 2

1 f 400.

Y

400.

Y clcl

Ycl (cm)• The correction is bigger for longer modules

TestTest• ~ 106 events (‘gg04’ production)• Redo the clustering with: 1) the same attenuation lengths of the generation 2) no extra correction along Y

• Problem: when I dropped CELE and cluster banks and I tried to redo the clustering starting from MCEL, I got energies a factor of 5 bigger than before ! (already at MCEL level; it is not a clustering problem)

• Divide all the cluster energies by 5 and see what happens

Test on Test on Before After

ConclusionsConclusions• The response is more uniform in the central part of the endcap, but decreases with increasing X and Y

• The decreasing toward the module ends (Y coordinate) is bigger than in the old MC; to be investigated (this is the reason, I guess, of the extra correction by Matteo & Stefano)

• With the help of Tommaso, we will compare data to MC looking for other possible differences to correct