This page describes preliminary results of the DELPHI collaboration. If you like to show them please ask for confirmation!
We have two analyses measuring mW by reconstruction of the W mass spectrum. The first analysis uses the WW -> lepton, neutrino, 2 jets channel. The second analysis uses the WW -> 4 jets channel. They reconstruct the events fully and get mW from a likelihood fit. In the hadronic channel all possible jet pairings are used. The following results are obtained:
Mixed decays (183 GeV):
mW = 80.506 +/- 0.255 (stat) +/- 0.060 (syst) +/- 0.030 (LEP) GeV
4 jets (183 GeV):
mW = 80.024 +/- 0.203 (stat) +/- 0.043 (syst) +/- 0.100 (int) +/- 0.030 (LEP) GeV
Result from 172 GeV data:
mW = 79.90 +/- 0.59 (stat) +/- 0.05 (syst) +/-0.10 (int) +/- 0.03 (LEP) GeV
161 GeV cross section:
mW = 80.40 +/- 0.44 (stat) +/- 0.09 (syst) GeV
All DELPHI results combined:
mW = 80.24 +/- 0.15 (stat) +/- 0.04 (syst) +/- 0.05 (int) +/- 0.03 (LEP) GeV
The 183 GeV analyses can be found in DELPHI
98-85 CONF 153.
The 172 GeV analyses are published in Eur. Phys. J C 2 (1998) 581
and you can get all the figures.
Mass spectrum in the WW->lvqq channel,
where the lepton is an identified electron (left) or muon (right).
Mass spectrum in the WW -> qqqq channel.
The points with the error bars represent the data, the yellow are the
Monte Carlo prediction for the WW signal, the red and green histograms
represent the different backgrounds.
