EW TASK FORCE MEETING ( 30-5-96)
 
  1. Muons
   . Imma showed her results using the single arm method for
     cross-sections and asymmetries .
     For cross-sections the results look coherent with the
     previous analysis, but the significance of the difference should be
     calculated taking into account the fraction of not overlapping evts.
     For asymmetries, the  results are coherent with the previous numbers
     and were compared with Henri's results during the meeting.
     For 2 energy points a two sigma effect was found:
     93 (peak-2)  and 95 (peak+2).
     Imma and Henri will check the event list to be able to calculate
     the exact significance of the difference.
 
      KORALZ problem (run 944 vs 1757, see previous minutes):
      Several checks have been made by Henri, Brigitte & Anne-Marie :
               - No difference at library level was found
               - No difference in the parameters used for the generation
               ( except Mh = 100,300)
 
     Andrea will check at the level of Kinematic cuts :
               - cos(theta) distribution(2 permil difference , err:0.9pm)
 
  2. Electrons
 
       Pere showed the cross-section distribution obtained (95) taking
     into account the efficiency dependence in cos(theta)* for the
     different energy point . The peak-2 point is now only one sigma
     off the SM  expectations (was 1.4 sigma).
       Henri has produced 90k s-channel electrons with KORALZ which
     should be available soon at CERN.
 
       Henri & Pere are checking the event list of bhabha's .
 
  3. Taus
 
        Still  some confusion about the available Monte-Carlo :
        Scanbook indicates some peak as peak-2 events at the MINI level.
        Be careful ...
        Andrea has introduced a nice page on the Web
        http://alephwww.cern.ch/~venturi/ew/mc_summary.html
        which  gives the list of the available Monte-Carlo.
 
  4.  Monte-Carlo (in production )
 
        - tau (95) p-2,p+2 ( geom 94)
        - tau (93) peak ( geant 321)
        - More muons have to be produced
        - Unibab in production in LYON (Ioana , Edwige)
          Production by Lee? Any news?
 
  5 . 90 data
 
        - It seems difficult to redo MC  with 90 geometry , therefore
          Henri suggested to drop the '90 statistics .
          In 90 there was a peculiar status
          of the detector (ex :muon ch. layer 2 missing).
          It needs the corresponding Monte-Carlo.
          Before dropping the data the effect on the fits should
          be checked
 
   Next meeting : June 6th 4pm room 2-1-034
 
 At the meeting we should clarify what we are going to put into the
 Warsaw paper. Time is short!!
 
 All minutes are now available on the Web.
 Go to the Aleph Meetings page and choose Electro Weak.
 The address is :
 
 http://alephwww.cern.ch/ALEPHGENERAL/schedules/electroweak/electroweak.html