STT meeting
 ===========
     Thursday, 27 May 1999, 13:00 to 14:00
          in the Ninth Circle

Agenda:
  * status/progress
  * Boston meeting
  * AoB


  
People present at Meeting:
==========================
Sailesh Chopra, Brian Connolly, 
John Hobbs, Harrison Prosper, Wendy Taylor, 
Silvia Tentindo-Repond,  Horst Wahl. 

1. status/progress:
-------------------
 Report on track fitting algorithm studies (John):
 
 John has finished his track fitting algorithm studies; D0note sumarizing his
 findings is in preparation -- nearly done. Timing studies partly done, to be
 finished in about ten days.
 Outline of algorithm studies:
  Data samples used: Z to b bbar with 0 and 2 additional interactions,
                     WH to jets with 0 additional interactions,
		     MB mix
  algorithms tried: static road with 4 SMT hits (SR4)
                    static road with 4 SMT hits (SR3)
		    dynamic road with 4 SMT hits (DR4)
                    dynamic road with 4 SMT hits (DR3)
		    all combinations with 4 SMT hits
		    all combinations with 3 SMT hits
		    
  criteria for judging algorithm performance:
           purity: = fraction of reconstructed tracks having only hits 
	             from one MC track
	   efficiency: fraction of tracks reconstructed among those with hits in
	               at least 3 layers and chisq > 3
	   trigger efficiency: for dedicated triggers of PAC98 trigger menu
	   
  Main findings:
    track efficiency vs pt: rather flat, best for SR3
                     vs impact parameter: flat for  b < 1mm, 
		                          but drop-off beyond that;
			  drop-off worst for SR (biases against large impact
			           parameters)
				   
  conclusion: 
    * need to accept 3 layers  		  
    * may need  to use DR3 for better efficiency for large imp. par.