Difference between revisions of "Feb. 22, 2008 Tracking CDC/FDC"

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(Agenda)
(Added Attendees and started on minutes)
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==Minutes==
 
==Minutes==
  
Attendees: ''TBD''
+
Attendees:  
 +
 
 +
@JLab: David L., Elton S., Tim W., Paul E., Simon T., Alex S., Mark I., Dan C.
 +
 
 +
@CMU: Curtis M., Yves, Matt B.
 +
 
 +
@FSU: Alexander O.
 +
 
 +
@IU: Beni Z., #delta;Matt S.
 +
 
 +
 
 +
===MC Resolutions From GEANT===
 +
David showed plots of the most recent tracking resolution results from the GEANT based Monte Carlo. These showed some noticable improvements
 +
especially in the forward direction. The fits included only CDC and FDC wires (no cathode strips). Plots of the residuals in the CDC and FDC as well as
 +
resolutions for 90<sup>o</sup> tracks for both parametric calculations and geant-based were shown. These indicated something was not understood
 +
for events with no smearing in both the CDC and FDC. David noted that the problem looks as though it may only be manifest in tracks that are nearly
 +
perpendicular to the wires. He will investigate further to track it down.
 +
 
 +
Also shown was a plot of the dE in the CDC for proton, kaon, and &pi; tracks with total momentum less than 1GeV/c. From a set of these, the threshold
 +
for reconstructing particles of the various types as a function of angle was made. This indicated about a 300 MeV/c threshold for protons and around
 +
200 MeV/c for Kaons both with some dependance on angle.
 +
 
 +
===EM Background Rates===
 +
David showed 4 plots indicating the EM background rates in the FDC, CDC, and TOF for both the March 2007 geometry and the current geometry.
 +
Dan noted that the center-most strips would be half-size so the values for the peak rates in those plots would need to be cut in half.
 +
 
 +
It was discussed whether additional studies would be needed prior to the March review. It was agreed that these would suffice with the one modification
 +
mentioned above.
 +
 
 +
===&pi;/K Separation via. Kinematic Fitting===
 +
Matt gave an update on the work he has been doing to study how well kinematic fitting could be used to separate &pi;'s and K's in a pair of similar
 +
channels from f<sub>2</sub>(1270) decays. The study's goal was to see how well events from the &pi;&pi;KK channel could be isolated from a
 +
background of &pi;&pi;&pi;&pi; events which are produced with a cross-section 100 times larger than the "signal".
 +
 
 +
Matt has implemented 2 of the sugestions from the last meeting:
 +
# Assume we cleanly identify the proton
 +
# Apply an "anticut" where the confidence levels of the other possible channels are below some limit (either 1% or 10%)
 +
 
 +
With these, he was able to show that with GlueX resolutions (March 2007) he could achieve a sample purity with only 4% background contaimination
 +
for the 10%CL anticut and <1% for the 1%CL anticut. These were at cost of throwing away about 50% and 65% respectivley of the true signals events.
 +
Note that these were done with no fiducial cuts and no information from the TOF. Matt will work on incorporating the TOF next as well as how
 +
they might reclaim the true events that were cut.
 +
 
 +
===BNL E852 Tracking Resolutions===
 +
 
 +
===3&pi; Resonance Generation/Simulation===
 +
 
 +
===Schedule of preparations===
 +
 
 +
===CDC Hardware Status===
 +
 
 +
===FDC Hardware Status===
 +
 
 +
===FDC Track Finder Status===

Revision as of 15:37, 22 February 2008

Agenda

  1. Status of MC resolution studies PDF (David)
  2. EM Background rates (David)
  3. Status of Kinematic Fitting (Matt)
    1. Signal Leakage in pi/K (new studies) pi/K Separation (GlueX doc-971)
    2. Previous talk pi/K Separation (GlueX doc-971)
  4. Status of PWA anchoring (Paul, Alexander)
    1. BNL-E852 tracking resolutions
      1. Pos-Res
      2. Neg-Res
    2. Three pi resonance generation & simulation
      1. gamma p -> a2(1320) n [pdf file]
      2. gamma p > X n where X contains: a1(1170), a2(1320), pi2(1670), pi1(1600) [pdf file]
      3. rebirth of pwa simulations
  5. DC and PID Review Schedule for preparations (Elton)
  6. CDC Hardware Status 22 February 2008
  7. FDC Hardware Status
  8. Update on segment-based track finding (Simon)[1]

Participating

Location

The meeting will be at 11:00am in Cebaf Center F324-325.

Telephone

To connect by telephone: 1.) dial:

800-377-8846 : US
888-276-7715 : Canada
302-709-8424 : International (not a free call!)

2.) enter participant code: 39527048# (remember the "#")

Video Conferencing

The room at JLab does not have video conferencing equipment installed.


Minutes

Attendees:

@JLab: David L., Elton S., Tim W., Paul E., Simon T., Alex S., Mark I., Dan C.

@CMU: Curtis M., Yves, Matt B.

@FSU: Alexander O.

@IU: Beni Z., #delta;Matt S.


MC Resolutions From GEANT

David showed plots of the most recent tracking resolution results from the GEANT based Monte Carlo. These showed some noticable improvements especially in the forward direction. The fits included only CDC and FDC wires (no cathode strips). Plots of the residuals in the CDC and FDC as well as resolutions for 90o tracks for both parametric calculations and geant-based were shown. These indicated something was not understood for events with no smearing in both the CDC and FDC. David noted that the problem looks as though it may only be manifest in tracks that are nearly perpendicular to the wires. He will investigate further to track it down.

Also shown was a plot of the dE in the CDC for proton, kaon, and π tracks with total momentum less than 1GeV/c. From a set of these, the threshold for reconstructing particles of the various types as a function of angle was made. This indicated about a 300 MeV/c threshold for protons and around 200 MeV/c for Kaons both with some dependance on angle.

EM Background Rates

David showed 4 plots indicating the EM background rates in the FDC, CDC, and TOF for both the March 2007 geometry and the current geometry. Dan noted that the center-most strips would be half-size so the values for the peak rates in those plots would need to be cut in half.

It was discussed whether additional studies would be needed prior to the March review. It was agreed that these would suffice with the one modification mentioned above.

π/K Separation via. Kinematic Fitting

Matt gave an update on the work he has been doing to study how well kinematic fitting could be used to separate π's and K's in a pair of similar channels from f2(1270) decays. The study's goal was to see how well events from the ππKK channel could be isolated from a background of ππππ events which are produced with a cross-section 100 times larger than the "signal".

Matt has implemented 2 of the sugestions from the last meeting:

  1. Assume we cleanly identify the proton
  2. Apply an "anticut" where the confidence levels of the other possible channels are below some limit (either 1% or 10%)

With these, he was able to show that with GlueX resolutions (March 2007) he could achieve a sample purity with only 4% background contaimination for the 10%CL anticut and <1% for the 1%CL anticut. These were at cost of throwing away about 50% and 65% respectivley of the true signals events. Note that these were done with no fiducial cuts and no information from the TOF. Matt will work on incorporating the TOF next as well as how they might reclaim the true events that were cut.

BNL E852 Tracking Resolutions

3π Resonance Generation/Simulation

Schedule of preparations

CDC Hardware Status

FDC Hardware Status

FDC Track Finder Status