Using new ACD merit variables in background rejection
Current background rejection
Prefilters:
Cut |
Purpose |
Gamma Effic |
Bkg Effic |
|---|---|---|---|
BasicTileCut |
Reject events with track pointing at struck tile: |
95.1% |
8.1% |
RibbonCut |
Reject events with track pointing at struck ribbon |
94.9% |
7.7% |
TotalTileEnergyCut |
Reject events with excess ACD total energy |
89.3% |
1.2% |
CornerCut |
Reject event in the corner gap of the ACD |
88.3% |
1.1% |
TileEdgeCut: |
Reject events at tile edges with decreased signal |
88.1% |
1.1% |
ClassificationTree:
Variable |
Importance |
AcdTotalTileEventEnergyRatio |
2034.17 |
Tkr1SSDVeto |
1201.47 |
CTBCORE |
812.28 |
AcdTkr1ActDistNorm |
575.06 |
AcdTkr1ActiveDistENorm |
476.57 |
AcdTotalEnergyNorm |
269.89 |
Tkr1ACDSideZ |
256.61 |
AcdActDistNorm |
118.93 |
Tkr1LATEdge |
107.11 |
AcdTileEnergyNorm |
106.51 |
AcdCornerDocaENorm |
81.52 |
AcdMaxTileEnergy |
74.32 |
AcdTileEventEnergyRatio |
73.48 |
AcdTkr1TileEnergyNorm |
25.67 |
AcdTileCount |
24 |
Using New Variables
AcdTkr1VetoSigmaHit is the probability of the "best" hit vetoing the track, expressed in "sigma". This is the sum in quadrature of contributions from the miss distance and the signal being less that 1 MIP. For MIP signals along the track projection this variable is 0.
Same plot, but with the X-axis remapped with log10( AcdTkr1VetoSigmaHit + 0.01)
VetoHit1 is
Cut |
Reason |
Gamma Effic |
Bkg Effic |
|---|---|---|---|
VetoHit1 < 5 |
Reject events with best rack pointing at struck tile/ribbon |
94.8% |
7.2% |
TotalTileEnergyCut |
Reject events with excess ACD total energy |
89.3% |
1.2% |
VetoGap1 < 2 |
Reject event in gaps of the ACD |
89.1% |
1.2% |
VetoHit < 2 |
Reject events if other track points at hit tile |
89.0% |
1.1% |