Updated Results from the In Situ Calibration Site in Bass ...
In-situ calibration with Zee events
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Transcript of In-situ calibration with Zee events
13/12/2007
In-situ calibration with Zee In-situ calibration with Zee eventsevents
Nikola MakovecGroup meeting
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OutlinOutlinee CSC Note EG-6, section Intercalibration
Motivation Data sample and event selection Description of the method
The fitting method Reference distribution
Method testing Results with misaligned and distorted geometry Conclusion
8 pages
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MotivatioMotivationnIn situ calibration of the EM calorimeter with
Zee events:
Intercalibration Non-uniformities
Temperature Purity Extra-material in front of the calorimeter
Local constant term ~0.5% (=0.20.4) Goal : 0.7% (TDR) Intercalibrate these regions to a level of 0.4%
Absolute energy scale Physics atlas program : ~0.1% W mass measurement : ~0.02%
LRL CCC
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Data sample and event Data sample and event selectionselection Data sample :
Trig1_misal1_csc11_V1.005144.PythiaZee.recon.NTUP.v12000601 Studies at the generator level
Trig1_misal1_csc11_V1.005144.PythiaZee.recon.NTUP.v13003002 Used after simulation and reconstruction
Event selection at least electrons The 2 leading should satisfy
pT>20GeV ||<2.4 IsEM(Medium)=true
80<Mee<100
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Description of the method (1)Description of the method (1)
Notation:
The fitting method: 2 step : Measurement
Minimising the following log-likelihood :
generalized least squared method is applied leading to an analytical solution.
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Description of the method (2)Description of the method (2)
The reference distribution
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Method testing (1)Method testing (1)
Done at the generator level Injected bias drawn from a Gaussian(,) Gaussian(0,2%)
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Method testing (2)Method testing (2)
Gaussian(,2%)
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Method testing (3)Method testing (3)
Expected constant term as a function of the luminosity
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Results with misaligned and distorted geometry (1)Results with misaligned and distorted geometry (1)
Gaussian(0,0%)
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Results with misaligned and distorted geometry (2)Results with misaligned and distorted geometry (2)
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Results with misaligned and distorted geometry (3)Results with misaligned and distorted geometry (3)
Gaussian(0,2%)
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Results with misaligned and distorted geometry (4)Results with misaligned and distorted geometry (4)
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ConclusioConclusionn With~200pb-1:
Constant term ~ 0.7% Absolute scale known with a precision of few
percent
Care of extrapolation to other energy spectrum (linearity?)
Amount of material in front of the detector : E/p Conversion Energy flow
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To do listTo do list
Corrections de la note : Fond? Forme Style et orthographe
Si vous avez un peu de temps: /exp/atlas/makovec/Notes/CSC-EG-6.pdf
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