January 24th, 2002 PMCS meeting 1

Junjie Zhu

University of Maryland

January 24th, 2002 PMCS meeting 2

• Introduction• Smearing Algorithm• Method used to determine smearing parameters from D0reco• Results from pmcs_em package 1. Z ee 2. W e • Summary

January 24th, 2002 PMCS meeting 3

• PMCS_EM package is used to fast simulate behaviors of EM objects• Since electrons and photons have almost the same behavior in EM calorimeter, they are smeared the same way•Smear electrons at generator level

January 24th, 2002 PMCS meeting 4

• Generator-level electrons are first extrapolated to the EM3 layer, and depending on their positions, different parameters are used to smear them

• For each electron, adjust the energy scale, smear energy, detector eta and phi

January 24th, 2002 PMCS meeting 5

• x: random number generated from Gaussion distribution

• a, b are energy scale constants

• C: Constant term S: Sampling term N: Noise term• : energy resolution• : detector eta resolution• : phi resolution

det

'

2 22

2

'

det det

*

*

*

*

gen

E

smear E

smear gen

smear gen

E a E b

S NC

E E E

E E x

x

x

Edet

January 24th, 2002 PMCS meeting 6

• Need to get the corresponding parameters from D0reco, assume D0reco is absolutely right (for now)• 14 Event Samples (single energy electrons)• D0reco and Reco_analyze Version: p10.11.00• Electron energy: 5, 10, 20, 30, 50, 80, 100, 120, 150, 200, 220, 250, 300, 400Gev• Each sample contains 6,000 events, no pile up, flat in space

January 24th, 2002 PMCS meeting 7

Electrons in EM3 layer are divided into six types:1. In CC, pass CPS, not in Crack region2. In CC, pass CPS, in Crack region (5% from both

sides)3. Only in EC, 4. In EC, pass one shower layer of FPS5. In EC, pass two shower layers of FPS6. Only in EC, Type 3 and 6 are different since they have different detecor acceptance, energy scale are alsosupposed to be different

det1.40 1.45

det2.5 4.0

January 24th, 2002 PMCS meeting 8

Electrons in other regions: 7. ICD region with 8. Very forward region with are not smeared and also not stored .

det1.14 1.40 det 4.0

January 24th, 2002 PMCS meeting 9

January 24th, 2002 PMCS meeting 10

January 24th, 2002 PMCS meeting 11

January 24th, 2002 PMCS meeting 12

January 24th, 2002 PMCS meeting 13

• Pmcs_em package are tested by two event samples:

1. 1000 Z ee events <MinBias>=2.5 2. 1000 W e events <MinBias>=2.5• Blue histogram for D0reco, Red histogram

for pmcs

January 24th, 2002 PMCS meeting 14

January 24th, 2002 PMCS meeting 15

January 24th, 2002 PMCS meeting 16

January 24th, 2002 PMCS meeting 17

January 24th, 2002 PMCS meeting 18

January 24th, 2002 PMCS meeting 19

January 24th, 2002 PMCS meeting 20

January 24th, 2002 PMCS meeting 21

January 24th, 2002 PMCS meeting 22

• Electrons in pmcs_em package seem to agree well enough with D0reco electrons• C, S and N getting from D0reco with big errors, need to derive it from real data• Have started tuning pmcs to real data•Code will soon be released