| Home » PANDA » PandaRoot » Tracking » Lhe Tracking: Kalman Task with STT, worse results Goto Forum:
	| 
		
			| Lhe Tracking: Kalman Task with STT, worse results [message #11269] | Sun, 05 December 2010 14:04  |  
			|  |  
	| Hallo everybody, 
 when I compare the results after the Kalman Task for the STT and TPC I get worse results with the STT code
 according to the reconstruction efficiency and the momentum resolution.
 
 The following parameters have been used:
 
 - Panda Root trunk version, revision 10334
 - Geant3
 - Box generator: myons with vertex (0,0,0)
 - theta = 60°, phi = 0:360°
 - one primary track per event, only primary tracks are taken into account in the analyses
 - 1e4 events
 - Lhe tracking package: ideal track finder + helix prefit + kalman task with correct particle hypothesis
 - MVD+STT or MVD+TPC+GEM tracking detectors, new MVD geometry: Mvd-2.1_AddDisks_FullVersion
 - STT helix hits are taken
 - transverse momentum: 200MeV/c -> total momentum 230.94MeV/c
 
 STT, 86% reconstruction efficiency, sigma 3MeV/c, background after Kalman
 
  The strange thing here is that the Kalman produces a lot of background. The dispersion is larger
 than 3*sigma of the helix prefit. One can even do a cut on the difference between helix prefit and
 Kalman result to enhance the fit quality. This is to my mind a strong evidence that something in the
 Kalman code for the STT does not work properly!
 
 TPC, 93% reconstruction efficiency, sigma 2MeV/c
 
  
 So I wonder if I do something wrong or this is just normal behavior. The smaller reconstruction efficiency is due to
 the Helix fit in the STT? Right? But I still do not understand why the results after the Kalman filter look so much different.
 
 greetings
 David
 |  
	|  |  | 
 
 Current Time: Fri Oct 31 22:09:15 CET 2025 
 Total time taken to generate the page: 0.00796 seconds |