Pass 6: Event Classes
The final chapter
Working Definitions
TRANSIENT: E > 100 MeV ~ 2 Hz. Maximize Aeff at low energy
 SOURCE: E> 100 MeV ~ .4 Hz. Maximize Aeff 500 MeV - 10 GeV
 DIFFUSE: E> 100 MeV ~ .1 Hz. Minimize High energy tail > 10 GeV

Will try to achieve a greater differentiation between
Classes then was the case in Pass 5
1
Basic Losses
CPFGamProb > 0 & CALSeal > 0
Total
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More optimal
CPFGamProb > max(.05, .55- .3* (CTBBestLogEnergy - 1.))
& CALSeal > 0
Total
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The 2 TKR Topoplogy Filters designed to kill sneak-through conversions,
Heavy Ions, and back-side entering range-outs
TKRShower > 0.
Total
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TKRShower > 0. & TKRHeavies > 0.
Total
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What the other PreFilters do
CALGamProb > 0.
Total
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The large losses in these Filters can
Be compensated for by taking the OR
TKRGamProb > 0. || CALGamProb > 0
TKRGamProb > 0.
Total
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Total
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Default CPF Seal and Special Event Filter
(TKRGamProb > 0 | CALGamProb > 0) &
TKRHeavies > 0. & TKRShower > 0. &
CPFGamProb > max(.05, .55- .3* (CTBBestLogEnergy - 1.)) &
CALSeal > 0.
Default Losses
Total
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This will be the applied to Source & Diffuse
The large loss below 100 MeV not appropriate for Transient
4
Combining TKRGamProb with CALGamProb
Pass 5
Pass 6
Pass 5 Cut variable: (2.*max(0.,TKRGamProb)/CTBBestLogEnergy + CALGamProb ) / (1 - .08*(CTBBestLogEnergy-1.))
Pass 6 Cut variable : 3.*(TKRGamProb + CALGamProb)/CTBBestLogEnergy
5
ALL Prob
This is another way of combining
the Shower & Topology Information
by way of a CT.
This doesn't use the combined
CALGamProb & TKRGamProb
6
This CT uses CalTkrComboCut
and this is the one that will be
used!
CTs agree that the correlation
between CALGamProb &
TKRGamProb is a good
discriminator
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Where the Signal and Backgrounds
are in the 2 GamProbs
Scan CPFGamProb
Increase cut on CPFGamProb
CPFGamProb > .2
Leaves 153781 Bkg
(10.6 Hz)
Scan CALGamProb
When events fail the TKR PreFilters
(TKRGamProb < 0)
set CALGamProb > .2
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When events fail the CAL PreFilters
(CALGamProb < 0)
Scan TKRGamProb
Set TKRGamProb > .2
When events Pass Both PreFilters
(CALGamProb > 0 & TKRGamProb > 0)
Set (CALGamProb + TKRGamProb) > 1.
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When events Fail Both PreFilters
(CALGamProb < 0 & TKRGamProb < 0)
Nothing to rescue
Pass 6 Transient Class
CPFGamProb > .2 & CALSeal > 0 &
((TKRGamProb < 0 & CALGamProb > .1) |
(TKRGamProb > .1 & CALGamProb < 0) |
(TKRGamProb+CALGamProb > .5))
Results: Bkg. Left = 29226 = 2.02 Hz
Bkg. Above 100 MeV = 14676 = 1.02 Hz
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Losses: ~ 25% below 100 MeV
Gamma and Background Spectra
Total
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For the next 2 Classes, only the
CT based combination of TKR
and CAL GamProbs will be used
One of the PreFilters Vetoes
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Source Class
Req. Transient Class
AllProb Knob
Use CT with CalTkrComboCut
.4 Hz - AllProb > .10 (!)
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Source Class
Remaining Background: All = 7400 (.51 Hz)
E > 100 MeV = 4837 (.33 Hz)
Gamma and Background Spectra
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Diffuse Class
(By far the hardest due to high
energy residual backgrounds)
AllProb > .4
Leaves: All = 1860 (.13 Hz)
E > 100 MeV = 1627 (.11 Hz)
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But….
E > 3000 MeV : 87 event (6.0 mHz)
Raising AllProb cut to .55
yields 40 events
26 events have McTkr1DirErr > .01
10 Fail CPFGamProb > .08*CTBBestLogEnergy
6 have (AcdActiveDist3D > 0 & AcdActDistTileEnergy > 1.7)
1 has (AcdActiveDist3D > 0 & AcdActDistTileEnergy > .2 & Tkr1SSDVeto == 0)
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High Energy Residual Backgrounds
Applying these cuts results in
AllProb > .4
Leaves: All = 978 (.068 Hz)
E > 100 MeV = 934 (.065 Hz)
No. Events > 3 GeV: 29 Events (2.0 mHz)
AllProb > .4 + Cuts
For Pass 5 this was 3 mHz.
This needs improvement!
Event Class Comparison
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Summary


Pass 6 improves on Pass 5
The basics for optimize Event Class
definitions are available
 Improvements needed to compensate for
mis-tracking at high energy
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