Difference between revisions of "Kinematic fitting charged particles 11/16/11"

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Look at events with exactly 5 tracks (3 positive, 2 negative) and look at sum of reconstructed 3-momentum from all tracks.
 
Look at events with exactly 5 tracks (3 positive, 2 negative) and look at sum of reconstructed 3-momentum from all tracks.
  
 
+
28% of events have exactly 5 tracks
  
 
[[Image:Pt_vs_pz.png]]
 
[[Image:Pt_vs_pz.png]]
 +
 +
2400 events in region outlined in red.

Revision as of 14:32, 16 November 2011

Reaction

Looking at an all charged particle final state to study the state of the tracking code: \gamma p -> pi+ pi+ pi- pi- p.

  • 50,000 events
  • svn revision 8540

Kinematic fit

All combinations of track hypotheses that produce the correct final state are kinematically fit. Constraint is overall conservation of 4-momentum.

  • 41% of events have sufficient particles (>=3 positive tracks, >=2 negative tracks)
  • Of these, 9% have kinematic fit confidence level>1% (4% of total events)


3-momentum

Kinematic fit is dependent on errors, PID. Try to simplify things...

Look at events with exactly 5 tracks (3 positive, 2 negative) and look at sum of reconstructed 3-momentum from all tracks.

28% of events have exactly 5 tracks

Pt vs pz.png

2400 events in region outlined in red.