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Contents Motivation Strategy Results Summary. Motivation Adding a constraint to the energy resolution leaves less freedom for the other parameters Current values for the noise term when left free to fit:. Strategy Determine the average RMS of noise events - PowerPoint PPT Presentation
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Thursday 1 March 2012
Ching Bon [email protected]
Determination of the Noise TermAnalysis of W-AHCAL CERN 2010 Data
Ching Bon Lam ([email protected])
Analysis of W-AHCAL CERN 2010 Data – Determination of the Noise Term W-AHCAL Analysis Meeting - Thursday 1 March 2012
2
Contents1. Motivation2. Strategy3. Results4. Summary
Ching Bon Lam ([email protected])
Analysis of W-AHCAL CERN 2010 Data – Determination of the Noise Term W-AHCAL Analysis Meeting - Thursday 1 March 2012
3
Motivation• Adding a constraint to the energy resolution leaves less freedom for the other parameters• Current values for the noise term when left free to fit:
𝜎𝐸
=𝑎√ 𝐸
⊕𝑏⊕𝑐𝐸
Data c (noise term)
5
Ching Bon Lam ([email protected])
Analysis of W-AHCAL CERN 2010 Data – Determination of the Noise Term W-AHCAL Analysis Meeting - Thursday 1 March 2012
4
Strategy1. Determine the average RMS of noise events2. Convert the average RMS from MIP to GeV3. Fit the energy resolution with a fixed noise term
Ching Bon Lam ([email protected])
Analysis of W-AHCAL CERN 2010 Data – Determination of the Noise Term W-AHCAL Analysis Meeting - Thursday 1 March 2012
5
Average Noise RMS1. Retrieve the noise events for every energy point2. Determine the RMSs of the energy sum distributions
3. Calculate the average noise RMS:Polarity runs <RMS> (MIP)
Positive 1.930
Negative 2.069
Ching Bon Lam ([email protected])
Analysis of W-AHCAL CERN 2010 Data – Determination of the Noise Term W-AHCAL Analysis Meeting - Thursday 1 March 2012
6
MIP to GeV 1. Determine the energy scaling factor: fit the detector response with the function2. Convert MIP to GeV
Polarity runs <RMS> (MIP) <RMS> (GeV)
Positive 1.930 0.274
Negative 2.069 0.262
Data c (noise term)
5
Ching Bon Lam ([email protected])
Analysis of W-AHCAL CERN 2010 Data – Determination of the Noise Term W-AHCAL Analysis Meeting - Thursday 1 March 2012
7
Energy resolution
After fixing the noise term• Fit values are more similar between and • might indicate underestimation of errors
𝜎𝐸
=𝑎√ 𝐸
⊕𝑏⊕𝑐𝐸
Χ 2=∑𝑖=1
𝑛 ( 𝑦 𝑖 ,𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑− 𝑦 𝑖 ,𝑚𝑜𝑑𝑒𝑙 )2
𝜎2
Before
After
Data a (stochastic) b (constant) c (noise)
(fixed)
(fixed)
Ching Bon Lam ([email protected])
Analysis of W-AHCAL CERN 2010 Data – Determination of the Noise Term W-AHCAL Analysis Meeting - Thursday 1 March 2012
8
SummaryRMS noise using electromagnetic energy scale:
Energy resolution with fixed noise term• Fit values are more similar between and • Increase in might indicate underestimation of errorsOutlookHow to determine the noise term for pions and protons?
Polarity runs <RMS> (MIP) <RMS> (GeV)
Positive 1.930 0.274
Negative 2.069 0.262
