p0%20Reconstruction%20Efforts

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p0 Reconstruction Efforts

• Rob Kroeger
• Sept 13, 2006

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To reconstruct single photon Xt_Fitter
the_Xt_Fitter(myGamCluster) if(the_Xt_Fitter.va
lid_photon) E0 the_Xt_Fitter.Photon_E0/1000.

position0 the_Xt_Fitter.Photon_pos1 To
reconstruct 2-bump cluster Xt_Fitter
the_Xt_Fitter(theIndexedPi0Bumps) if(the_Xt_Fitte
r.valid_Pi0)
E0 the_Xt_Fitter.Photon_E0/1000.

E1 the_Xt_Fitter.Photon_E1/1000.
position0
the_Xt_Fitter.Photon_pos0
position1
the_Xt_Fitter.Photon_pos1
double myCalibEnergy0

myCalibrator-gtenergyOf(E0,position0)

double myCalibEnergy1
myCalibrator-gtenergyO
f(E1,position1)

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To split one bump theIndexedBump.insert(stdmaplt
TwoCoordIndex, EmcBump
BbrPtrLessgtvalue_type
(theCurrMaximaTCI, currBump)) bool
split_one_bump true Xt_Fitter
this_Xt_Fitter(theIndexedBump, split_one_bump) if
(this_Xt_Fitter.valid_Pi0) double E0
this_Xt_Fitter.Photon_E0/1000.
double E1
this_Xt_Fitter.Photon_E1/1000.
HepPoint position0

this_Xt_Fitter.Photon_
pos0
HepPoint position1

this_Xt_Fitter.Photon_pos1
double
myCalibEnergy0
myGamCalibrator-gtenergyOf
(E0,position0)
double myCalibEnergy1

myGamCalibrator-gtenergyOf(E1,position1)

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The GFLASH parameterization was used
z
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WHY?
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?2 fit to Grindhammer form
Sum over slices in longitude.
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Each trapazoidally shaped pad devided into eight
right-triangles
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Bogus Fast Shower Parameterization, D. Bernard
BABAR Note 476
Transverse distribution approximated by sum of
Grindhammer terms
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Photon Reconstruction
Angular Reconstruction Error 1? reco compared to
prod code
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Run 4
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Run 4
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Run 4
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Splitting p0 merged to one bump

• Attempt to estimate axis of decay

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One Bump merged Pi0 candidates in
MergedPi0Tight