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.