Difference between revisions of "Mattione Update 09072011"
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| − | == FCAL Reconstruction == | + | == Summary == |
| + | * OBJECTIVE: I'm updating the reconstruction uncertainties to improve the particle-ID algorithms and support the kinematic fitting analyses. | ||
| + | |||
| + | * PLAN: I'm comparing the generated and reconstructed track parameters in the TOF, BCAL, and FCAL systems to determine the uncertainties. | ||
| + | |||
| + | * STATUS: I've almost finished getting the comparisons, selected results are shown below. There is a bug in the FCAL time reconstruction, the FCAL energy and TOF time uncertainties are significantly underestimated. | ||
| + | |||
| + | == FCAL Time Reconstruction == | ||
* The reconstructed FCAL time is significantly offset from the simulated times. | * The reconstructed FCAL time is significantly offset from the simulated times. | ||
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--------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------- | ||
-8.0 61.7 625.3 -44.8 343.8 3123.6 3142.732 18.8 1 1 1 //Photon generated at target center (0, 0, 65), so path length = 563.744 and t should be = 18.8 | -8.0 61.7 625.3 -44.8 343.8 3123.6 3142.732 18.8 1 1 1 //Photon generated at target center (0, 0, 65), so path length = 563.744 and t should be = 18.8 | ||
| − | //additional hits present but truncated | + | //similar, additional hits were present but were truncated |
DFCALHit: | DFCALHit: | ||
| Line 23: | Line 30: | ||
---------------------------------------------- | ---------------------------------------------- | ||
44 26 -12.0 60.0 42.050 21.082 | 44 26 -12.0 60.0 42.050 21.082 | ||
| − | //additional hits present but truncated | + | //similar, additional hits were present but were truncated |
</pre> | </pre> | ||
| − | * In programs/Simulation/HDGeant/hitFCal.c the times saved to the s_FcalTruthShowers_t and s_FcalTruthHit_t objects | + | * In programs/Simulation/HDGeant/hitFCal.c the times saved to the s_FcalTruthShowers_t and s_FcalTruthHit_t objects are different: the s_FcalTruthHit_t times (which are later smeared and converted to DFCALHit objects) are increased to account for what looks like light propagation to the PMTs (line ~192). Perhaps this isn't being taken into account in the DFCALCluster reconstruction code??? I'm not really familiar with it, so I'm hoping that someone who is will take a look at this. |
| + | |||
| + | == FCAL Energy Uncertainty == | ||
| + | |||
| + | * Difference between reconstructed and thrown photon energy, vs. photon energy. | ||
| + | [[Image:Mattione_Update_09072011_FCAL_DeltaEVsE.gif|thumb|left|600px]] | ||
| + | <br style="clear:both;"/> | ||
| + | |||
| + | * Next, the above histogram was fit to Gaussian functions, and the uncertainties are plotted with the points below. The function shows the FCAL shower energy uncertainty as currently used in the reconstruction code. | ||
| + | [[Image:Mattione_Update_09072011_FCAL_SigmaEVsE.gif|thumb|left|600px|Points: Fits to MC, Function: Current Uncertainty]] | ||
| + | <br style="clear:both;"/> | ||
| + | |||
| + | == TOF Time Uncertainty == | ||
| + | |||
| + | * Time Uncertainty (in reconstruction code, the particle time uncertainty at the vertex is set to 80 ps). | ||
| + | [[Image:Mattione_Update_09072011_TOF_SigmaT.gif|thumb|left|600px]] | ||
| + | <br style="clear:both;"/> | ||
Latest revision as of 13:35, 7 September 2011
Summary
- OBJECTIVE: I'm updating the reconstruction uncertainties to improve the particle-ID algorithms and support the kinematic fitting analyses.
- PLAN: I'm comparing the generated and reconstructed track parameters in the TOF, BCAL, and FCAL systems to determine the uncertainties.
- STATUS: I've almost finished getting the comparisons, selected results are shown below. There is a bug in the FCAL time reconstruction, the FCAL energy and TOF time uncertainties are significantly underestimated.
FCAL Time Reconstruction
- The reconstructed FCAL time is significantly offset from the simulated times.
- hd_dump of DFCALShower, DFCALTruthShower, and DFCALHit. Note that both the DFCALShower and DFCALHit times are ~2+ ns greater than the DFCALTruthShower times.
Event: 1 DFCALShower: E(GeV): X(cm): Y(cm): Z(cm): t(ns): -------------------------------------------- 3.27 -8.27 63.70 642.36 21.16 //Photon generated at target center (0, 0, 65), so path length = 580.922 and t should be = 19.377 DFCALTruthShower: x(cm): y(cm): z(cm): px(MeV/c): py(MeV/c): pz(MeV/c): E(MeV): t(ns): primary: track: type: --------------------------------------------------------------------------------------------- -8.0 61.7 625.3 -44.8 343.8 3123.6 3142.732 18.8 1 1 1 //Photon generated at target center (0, 0, 65), so path length = 563.744 and t should be = 18.8 //similar, additional hits were present but were truncated DFCALHit: row: column: x(cm): y(cm): E(MeV): t(ns): ---------------------------------------------- 44 26 -12.0 60.0 42.050 21.082 //similar, additional hits were present but were truncated
- In programs/Simulation/HDGeant/hitFCal.c the times saved to the s_FcalTruthShowers_t and s_FcalTruthHit_t objects are different: the s_FcalTruthHit_t times (which are later smeared and converted to DFCALHit objects) are increased to account for what looks like light propagation to the PMTs (line ~192). Perhaps this isn't being taken into account in the DFCALCluster reconstruction code??? I'm not really familiar with it, so I'm hoping that someone who is will take a look at this.
FCAL Energy Uncertainty
- Difference between reconstructed and thrown photon energy, vs. photon energy.
- Next, the above histogram was fit to Gaussian functions, and the uncertainties are plotted with the points below. The function shows the FCAL shower energy uncertainty as currently used in the reconstruction code.
TOF Time Uncertainty
- Time Uncertainty (in reconstruction code, the particle time uncertainty at the vertex is set to 80 ps).
