LISTSERV 16.5 - LCD-SIM Archives

Date: Fri, 23 Apr 1999 09:56:23 -0700
From: "Michael T. Ronan" <[log in to unmask]>
Subject: Re: Track finding in ttbar events
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To: Eugene Guillian <[log in to unmask]>
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Organization: Lawrence Berkeley National Laboratory
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Gene,

  I believe the problem is associated with the new track fitting in
lcd0.97. You can see from the slides on my home page

	http://obsidian.lbl.gov/~ronan/

that the track finder is finding an average of about 40 charged tracking
in ttbar events.

  You probably don't need track fitting at this stage. The momentum
resolution coming out of the track finder is 0.15% in ttbar events.

  Please see below, from a previous mail message to David Wagner, how to
turn OFF track fitting. Please let me know if you'd like me to re-attach
the TrackReco class.

Mike Ronan



David,

  I've attached a class which runs the lcd0.97 reconstruction with
fitting turned OFF. It has a line

        // Turn off track fitting
        addReconTrks.setNoFitting();

after creating the AddReconTrks process.

To replace the standard version in your analysis do the following

  ...
  // import hep.lcd.recon.tracking.*;
  import hep.lcd.util.driver.*;
  ...

  public class LCDDriver extends Driver
  {
    public LCDTrackDriver()
    {
      add(new TrackReco()); 
      add(new TrackAnalyzer());
    }
  }

That is, this modified version of TrackReco is NOT in the
hep.lcd.recon.tracking package so comment out the import line. Put
TrackReco.java and TrackReco.class in your main jas directory along with
your LCDDriver.

Please let me know if you have any problems.
Mike




/* TrackReco.java

                Find and reconstruct tracks.

 Created by  Mike Ronan  Dec '98   Picks up LCD events within JAS
framework and
                                   reconstructs tracks using 3D pattern
recognition software.
 Modified by

 */

import hep.lcd.recon.tracking.*;
import hep.lcd.util.driver.*;


/**   Picks up LCD events within JAS framework and
 * reconstructs tracks using 3D pattern recognition software.
 */
public class TrackReco extends Driver
{
    boolean Hstd = true;

    public TrackReco()
    {
        this(Hstd);
    }
    public TrackReco(boolean hist)
    {
        System.out.println("");
        String text = "TrackReco  version 0.9.7"+"\n"+
            "  Running hep.lcd version "+hep.lcd.Version.getVersion();
        System.out.println(text); out.println(text);
        System.out.println(" Track reconstruction using TPC and CCD
detectors - ");

        // Finds tracks in main tracker.
        tracker = new hep.lcd.recon.tracking.tpc.TPCReco(true);

        // Assign Vertex Detector hits to tracks found in main tracker.
        vertexDetector = new
hep.lcd.recon.tracking.ccd.CCDReco(tracker,true);

        // Add reconstructed tracks to event
        AddReconTrks addReconTrks = new
AddReconTrks(tracker,vertexDetector,true);


        // Add processes
        add(tracker);
        add(vertexDetector);
        add(addReconTrks);
    }

    /**
     * Used for standalone reconstruction
     */
    public static void main(String[] argv)
    {
        try
            {
                hep.analysis.Job job = new
hep.analysis.Job("TrackReco");
                job.setEventSource(new
hep.lcd.io.jas.LCDEventSource(argv[0]));
                job.addEventAnalyzer(new TrackReco());
                job.go();
            }
        catch (jas.jds.module.ModuleException x) { x.printStackTrace();
}
    }


    Tracker tracker;
    VertexDetector vertexDetector;
}