BCAL reconstruction 10/19/11
Contents
Update
- 1234 segmentation now an option in reconstruction code
- New algorithm comparable to or better than KLOE algorithm in most test I tried
- Will be checked in soon
Changes
- More flexible DBCALGeometry allows 1234 summing (checked-in)
- Change weighting when averaging quantities to form cluster
- Improve error estimation
- Tune parameters
- Fix various bugs
- Change in KLOE algorithm to min energy threshold of cluster to make the two algorithms match
Single photon event sample
45000 events, energy uniformly distributed from .05-2.05 GeV, angles from 10.8-118. Exclude all events with tracking hits, since we can't expect to reconstruct a photon in this case. All results with 1234 summing.
Efficiency
Both algorithm have ~99.5% efficiency.
Energy resolution
These plots use E_raw, not the corrected/calibrated E.
KLOE:
im
GlueX:
im
Timing resolution
Angular resolution
Number of showers reconstructed
Single pi0 event sample
~64000 pi0's isolated from a bggen sample using extract_ptype_hddm plugin.
Again exclude any events with tracking hits.
Hard to get an exact count of how many pi0's are reconstructed/reconstructable, so I tried two different methods.
Method 1
Use DTwoGammaFit to fit two photons to pi0 mass. The problem with this is that it relies on having correct errors, which we don't quite have yet.
Just count the number of events where there is a pi0 fit with confidence level > 10%.
- GlueX algorithm: 37163 good pi0 fits : 72% efficiency (excluding events with tracking hits)
- KLOE algorithm: 34322 good pi0 fits : 66% efficiency
Energy and angular resolutions are roughly the same
Method 2
Look at the two most energetic photons in an event. If the combined four-momentum falls "close" to the thrown pi0 four-momentum, count this a "good" reconstructed pi0.
- GlueX: 38342 good pi0's=74% efficiency
- KLOE: 36083 good pi0's=70% efficiency
b1pi event sample
10000 b1pi events from genr8.
Can count the number of reconstructed BCAL photons "close" to thrown photons.
- GlueX: 8266 "good" reconsructed BCAL photons/120
- KLOE:
Vertex spread.
