PandoraAnalysis
01.02.01
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PandoraPFACalibrator is a processor to aid calibration of PandoraPFA. More...
#include <PandoraPFACalibrator.h>
Public Member Functions | |
virtual Processor * | newProcessor () |
virtual void | init () |
Called at the begin of the job before anything is read. More... | |
virtual void | processRunHeader (LCRunHeader *run) |
Called for every run. | |
virtual void | processEvent (LCEvent *evt) |
Called for every event - the working horse. | |
virtual void | check (LCEvent *evt) |
Check. | |
virtual void | end () |
Called after data processing for clean up. | |
PandoraPFACalibrator is a processor to aid calibration of PandoraPFA.
There are three sets of constants that need to be calibrated: i) CaloDigi raw hit to GeV ii) PandoraPFA energy in GeV -> MIP equivalent conversion iii) PandoraPFA MIP equivalent -> PFO energy One might expect that factor iii) is the reciprocal of factor ii). However, due to the isolation cuts used in PandoraPFA this is not quite the case.
MC Samples:
o the calibration constants will depend on the Mokka ECAL and HCAL drivers, the GEANT4 physics list, and potentially the version of GEANT4 used to generate the events. o to calibrate PandoraPFA generate the following samples with the same version of Mokka/Geant4 used for the main event samples: o 10000 10 GeV photons with flat phi and flat cosine(theta) distributions o 10000 10 GeV K0L with flat phi and flat cosine(theta) distributions o 10000 10 GeV mu+/-
Calibration Procedure:
i) Calibration of Mokka hits o Using the photon sample, tune the calibration parameters in digitisation processor e.g. <parameter name="CalibrECAL" type="FloatVec">XX YY</parameter> to so that the histogram fCalEnergy is centred on 10 GeV. It is recommended that the calibration constants for the different layers should be in the ratio of the absorber thicknesses, i.e. 1:2 for ILD_o1_v05. o Repeat with the 10 GeV KL sample to fix <parameter name="CalibrHCAL" type="FloatVec">ZZ</parameter> ii) PandoraPFA MIP calibration o Using the muon sample, tune the parameters: <parameter name="ECALMIPcalibration" type="float">AA</parameter> <parameter name="HCALMIPcalibration" type="float">BB</parameter> so that fEcalMIPcorr and fHcalMIPcorr peak at approximately one. This set the scale for the energy deposited by a "minimum ionizing particle". iii) PandoraPFA ECAL/HCAL calibration o Using the photon sample run PandoraPFA and PandoraPFACalibrator and determine <parameter name="ECalToEMGeVCalibration" type="float">XX</parameter> <parameter name="HCalToEMGeVCalibration" type="float">YY</parameter> so that fPFA peaks at 10 GeV. It is recommended to set the response to hadrons to be the same as that for EM showers, i.e. ECalToEMGeVCalibration = HCalToEMGeVCalibration o Using the K0L sample, examine the profile of a plot of ECALToHAD energy vs HCALToHAD energy, expecting the profile to be a straight line of gradient -1, intercepting both axes at 10GeV. However, it may be necessary, for optimal jet energy resolution, to deweight the ECALToHAD contribution. Set the parameters below accordingly: <parameter name="ECalToHadGeVCalibrationBarrel" type="float">AA</parameter> <parameter name="ECalToHadGeVCalibrationEndCap" type="float">BB</parameter> <parameter name="HCalToHadGeVCalibration" type="float">CC</parameter>
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virtual |
Called at the begin of the job before anything is read.
Use to initialize the processor, e.g. book histograms.