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Introduction of my work AYAKO HIEI (AYA) Hiroshima Univ 2008/5/30. me. Motivation : ALICE & PHOS. Muon Spectrometer. Particle Detector. Inner Tracking System. Measurement feasible region:5-80MeV energy resolution @1GeV :3%. Tracking Chamber. We can operate PHOS
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Introductionof my work AYAKO HIEI (AYA)Hiroshima Univ2008/5/30 me
Motivation : ALICE & PHOS Muon Spectrometer Particle Detector Inner Tracking System Measurement feasible region:5-80MeV energy resolution @1GeV :3% Tracking Chamber We can operate PHOS By remote control without being influenced by a magnetic field. Magnet PHOton Spectrometer We have to calibrate each crystal ! (56×64×5=17920) :is a electromagnetic calorimeter :consist of 5 module. … 1 module consist of 56×64 PWO crystal … AYA / Introduction of my thesis work
How to calibrateenergy • For Example • Test Beam (Energy) • LED (signal level or fluctuation) • Inclination of energy distribution • MIP ,Minimum Ionization Particle(Energy) ※e.g.cosmic ray • Particle by collision (e.g. Invariant mass) etc… π0invariant mass peak → γ + γ (98%) ※Short life time π0 Mγγ count θ Eγ2 Reconstructed invariant mass[MeV] 134MeV Eγ1 In General use the incident particle of known behavior to a crystal AYA / Introduction of my thesis work
Energy calibration using pi0 mass peak π0 Mγγ π0 Mγγ θ θ Eγ2 GOOD Eγ2 Eγ1 Eγ1 BAD One of the two is fixed. GOOD Dead channel?? count GOOD mis calibration?? For exsampe Invariant mass[MeV] 134MeV 134MeV 110MeV AYA / Introduction of my thesis work
In order to make this method establish NOW I try • It is necessary to: • Investigate whether the peak positions are in agreement or not, and then the statistical error. (using simulation) • Investigatehow correct can we calibrate using only γevent on simulation, and using only pi0 event. and using collision event. etc AYA / Introduction of my thesis work
Simulated collision p p • pp collision • √S=14TeV • Event generator : PYTHIA • Event Bias : Minimum Bias • Number of Event : 4M • Noise with a Gaussian with the RMS=4MeV • Assumed a perfect calibration • for each crystal noise →I have to apply some “cut”. ONLY PHOS AYA / Introduction of my thesis work
Reconstructed pi0 mass histogram : NO CUT What is this structure? AYA / Introduction of my thesis work
The structure consists of noise mainly. (1) (2) (3) Noise with a Gaussian with RMS = 4MeV (4) (5) (6) AYA / Introduction of my thesis work
Reconstructed pi0 mass histogram : apply CUT • I apply • pT>1GeV/c • α<0.8 1876 ±941 pi0 Statistics are insufficient. for investigating the mass depending on one crystal and SO … AYA / Introduction of my thesis work
The crystals are grouped in 8×7 0.1261 ± 0.0023[GeV/c2] The peak position are in agreement with each other within the statistical error Of 1~2%,with the perfect calibration 0.1282 ± 0.0015 [GeV/c2] BUT! AYA / Introduction of my thesis work
NOW I investigate the following group y 54 module 3 crystal number ※ALICE Coordinate system 0 x 0 63 crystal number I want to see! (I have just try it now) Maybe a difference comes out most. because of Influence of a shower leak or clustering 0.1282 ± 0.0015 [GeV/c2] 0.1261 ± 0.0023[GeV/c2] AYA / Introduction of my thesis work
There are many things done still more NOW I try • It is necessary to: • Investigate whether the peak positions are in agreement or not, and then the statistical error. (using simulation) • Investigatehow correct can we calibrate using only γevent on simulation, and using only pi0 event. and using collision event. etc AYA / Introduction of my thesis work
Köszönöm for LISTENING AYA / Introduction of my thesis work
BACK UP : Trigger for cosmic ray ALICE COsmic-Ray Detector (ACORD) AYA / Introduction of my thesis work
BACK UP : component E Primary Detecting element Data acquisition System DAQ E’ AYA / Introduction of my thesis work
BACK UP : signal flow Signal Sampling count Number of sample : 70 Sampling frequency : 10MHz 2 Shaper!!! AYA / Introduction of my thesis work
BACK UP AYA / Introduction of my thesis work
BACK UP : shower shape 1 GeV electron electron cosmic ray By Chuman thesis punch through μ hadronic shower AYA / Introduction of my thesis work