Tuesday 8 September 1998
                                                Ian Tomalin


                MINUTES OF THE 20TH BEW MEETING
               =================================

  Agenda
 --------
   G. Dissertori  : Hadronic X-section analysis from Wolfgang Krebs 
   M.N. Minard    : 8-parameter S-matrix fit
   M. Swynghedauw : Z' fit results 
   I. Tomalin     : Status of paper
   All            : Status of everything

-----------------------------

G. Dissertori  : Hadronic X-section analysis from Wolfgang Krebs 
=================================================================

  Wolfgang has analysed 80**pb-1 of 189 GeV data. Measures exclusive 
qq cross section to be 19.1 +- 0.6 pb, in good agreement with
S.M. (19.2) and Marie-Noelle's measurement.
  Confirms observation that visible mass distribution in data
agrees with MC in Z return region, but is 1.5% too low for
non-radiative events. This is not understood. Marie-Noelle says
discrepancy is not present in charged tracks and does not depend
on polar angle. Wolfgang shows however that it does not introduce
a systematic bias in cross section measurement.

M.N. Minard    : 8-parameter S-matrix fit
==========================================

  Marie-Noelle has done 8 parameter S-matrix fit (assumes
lepton universallity). If gamma-Z interference is measured
from fit, then error on Z mass decreases from 11 MeV to
6 MeV to 3.5 MeV as one goes from LEP1 to LEP1 + 130-172
to LEP1 + 130-183 respectively. Error on Z mass is approaching
that obtained in fit to LEP1 data taking gamma-Z interference
from theory.
  Marie-Noelle wishes to check dependence of results on
alpha_QED(s). Will show final results to BEW meeting in near
future and then to Thursday meeting.

M. Swynghedauw : Z' fit results
================================

 Using cross section and asymmetry measurements from paper,
Marc has obtained limits on Z' in various models (E6, LR, SSM).
In models where there are two parameters (e.g. M_Z' and theta),
discussion as to whether to set limits considering theta
as free parameter or not. Conclusion, should consider it free
unless specific model considered where it takes certain value.
Marc will check what CDF do.
  Limit for sequential Z' is much better than for other models.
(Event beats CDF). Marc is investigating why this happens.
  When these two issues understood, analysis will be presented
again with accompanying writeup. Should then be ready for
Thursday meeting.

I. Tomalin: Status of Paper
===========================

  Leptonic and Hadronic sections:
     Done   : Beautiful figs. for leptons and hadrons.
     Missing: Tables of systematics and clarifications
              of text for leptons and hadrons.

  c-cbar cross section:
     Done   : Clarifications of text
     Missing: Better assessment of systematics
              Cross check using R_c measurement at Z0.

  b-bbar cross section:
     Missing: Clarification of text.
              Final figures.

  contact terms:  
    Done: Included ref. to CDF/HERA/low energy exp.

  sneutrino limit:
    Done: New figure of limit with smaller mass binning.

  leptoquarks:
    Missing:  Understand if two leptoquark programs are
              compatable.


Status of Everything
====================

  Soon expect the following:

    Direct search for excited leptons from T. Metcalf
      => Excited lepton paper.

    A_FB(cc)         from C.Goy
    Z' (final)       from M.Swynghedauw
    S-matrix (final) from M.-N. Minard
      => BEW paper if finished in time.
    
  Will be shown at BEW/Thursday meetings in near future.


Next Meeting: ALEPH WEEK - 22nd September at 16:00 in MAINZ 
============================================================