Difference between revisions of "FCAL Reconstruction in b1pi events 03/06/2012"
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(Created page with "Thrown photons: Image:PhotonEvsTheta thrown FCAL Feb12.png Reconstructed photons Image:PhotonEvsTheta recon FCAL Feb12.png Questions: * Why are so many "photons" reco...") |
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| − | Thrown photons | + | ===Thrown photons=== |
[[Image:PhotonEvsTheta thrown FCAL Feb12.png]] | [[Image:PhotonEvsTheta thrown FCAL Feb12.png]] | ||
| − | Reconstructed photons | + | ===Reconstructed photons=== |
[[Image:PhotonEvsTheta recon FCAL Feb12.png]] | [[Image:PhotonEvsTheta recon FCAL Feb12.png]] | ||
| − | Questions | + | ===Questions=== |
* Why are so many "photons" reconstructed? How can we reduce this? | * Why are so many "photons" reconstructed? How can we reduce this? | ||
* What is the actual reconstruction efficiency? | * What is the actual reconstruction efficiency? | ||
| Line 14: | Line 14: | ||
** Can we recover converted photons? | ** Can we recover converted photons? | ||
* Energy resolution, etc. | * Energy resolution, etc. | ||
| + | |||
| + | ===1 GeV photon events=== | ||
| + | Mihajlo in GlueX-doc-823 (2007) says for 1 GeV photons: | ||
| + | * 99.6% efficiency for photons that reach FCAL | ||
| + | * 37% photon conversion before FCAL | ||
| + | * Taking into account single clusters from photons that converted close to the FCAL face, the overall photon reconstruction efficiency was estimated to be 77% | ||
| + | * 4% energy resolution at 1 GeV | ||
| + | |||
| + | Has anything changed since 2007? How does b1pi sample differ from single photon sample? | ||
| + | |||
| + | ===Efficiency=== | ||
| + | Energy distribution of thrown photons: | ||
| + | * Black=all thrown photons | ||
| + | * Red=photons which reach the FCAL without converting (determined using DFCALTruthShower object) | ||
| + | * Blue=photons which reach the FCAL without converting AND are reconstructed successfully (fabs(theta_thrown - theta_recon) < .004 && fabs(phi_thrown - phi_recon) < .08) | ||
Revision as of 19:15, 6 March 2012
Thrown photons
Reconstructed photons
Questions
- Why are so many "photons" reconstructed? How can we reduce this?
- What is the actual reconstruction efficiency?
- How many photons reach the FCAL without converting?
- Efficiency for non-converting photons?
- Can we recover converted photons?
- Energy resolution, etc.
1 GeV photon events
Mihajlo in GlueX-doc-823 (2007) says for 1 GeV photons:
- 99.6% efficiency for photons that reach FCAL
- 37% photon conversion before FCAL
- Taking into account single clusters from photons that converted close to the FCAL face, the overall photon reconstruction efficiency was estimated to be 77%
- 4% energy resolution at 1 GeV
Has anything changed since 2007? How does b1pi sample differ from single photon sample?
Efficiency
Energy distribution of thrown photons:
- Black=all thrown photons
- Red=photons which reach the FCAL without converting (determined using DFCALTruthShower object)
- Blue=photons which reach the FCAL without converting AND are reconstructed successfully (fabs(theta_thrown - theta_recon) < .004 && fabs(phi_thrown - phi_recon) < .08)
