STATUS OF D ANALYSIS - MJL - 10/22/92

1) A summary of the vertex cuts used in my nominal analysis:
   a) 1st pass
       hadron trigger bit (trig 9)
       < 3 mubits (i.e. < 3 muon counters fired along track)
       fastsi impact parameters > 1.5 mils
       distance of closest approach <= .07"
       |y-interaction| <= .025"
       #yhits >= 6 and #uvhits >= 6
       |xtgt| <= 2"
       |ytgt| <= .05"
       zvtx >= .10"
       b1,b2 >= .003"
   b) 2nd pass (as above plus)
       y-176" and y-236" >= 4.5"
       (b1-b2)/error >= 4 (about b1-b2 >= .006")
       |yint/error| <= 80 (about .008")
       tau/error >= 6.25 (about .4 ps)
   c) ntuple cuts
       tau/error >= 12.5 (about .8 ps)
2) The trigger processor efficiency has been checked for the
   nominal cuts using the processor simulation program from
   Jeppeson and gives 86% for these cuts.
3) The fitting proceedures are still somewhat unstable but
   will improve soon. Numerous methods including PAW based,
   Q-based with HPL/FI or NEWFIT, and standalone MINUIT
   programs are being looked at.
4) An initial study of the A-dependence for different lifetime
   cuts has been done and gives the following:
                     Counts
    tau/error cut   Be   Au    Ratio(Au/Be)     Alpha
    -------------   ---  ---   ------------   ---------
      >= 9.5        658  481   .62+/-.04      .84+/-.02
      >= 12.5       475  328   .58+/-.04      .83+/-.02
      >= 15.5       311  270   .73+/-.06      .90+/-.03
 * changing processor efficiency has not been folded in yet
   and the fits are not very satisfying yet.
5) We are looking at the Xf and Pt dependences but must firm
   up the peak fitting before we can do anything serious about
   the Xf and Pt dependence of the A-dependence.
6) A number of figures of general interest have been made including:
   - monte carlo mass shapes for the four different PID choices
     for the pair (having thrown e.g. K-Pi+)
   - four PID choice mass spectra for Be and Au with the nominal
     cuts
   - four PID choice mass spectra with RICH PID showing poor RICH
     efficiency (internal consumption only)
   - sideband corrected lifetime plots for monte carlo, Be, and Au
     showing fits that give the correct D lifetime within
     uncertainties.
   - K-Pi+ and K+Pi- mass spectra for Be and Au for the three lifetime
     cuts of #4 above.
   - 20 or 30 silicon-pix and 3d-silicon pix pictures of D events.
7) No further progress on putting decay into the monte carlo or determining
   the hodoscope and calorimeter trigger efficiency contributions.
   Analysis of 1000 Amp tapes is in progress but about 1-1/2 weeks were
   lost up until today while I sat in meetings.
8) I will fax out my talk and some of the newer figures listed above to
   the various institutions. I will start by sending it to Martin at
   Fermilab; others who want copies should contact me and supply a fax
   number. I may be able to arrage postscript files on an individual
   basis, e.g. to get a higher quality figure for the Fermilab review.