(DELPHI experiment, CERN Geneva, Switzerland 1987-1990).
In addition to a heavy involvement in the preparation studies (detector simulations)
to determine the sensitivity for certain physics processes and the coordination of the
offline analysis processing, my main analysis effort was focused on the following two subjects :
This project, of which I was workgroup coordinator, was aimed at the development
of physics criteria to detect the decay of a light minimal standard model Higgs particle.
The main focus was here at 4-lepton events and events consisting of 2 leptons and 2 jets.
In case no positive signal was observed, an increasing lowerlimit for the Higgs mass was
determined, within the framework of the standard model, based on the steadily increasing
number of observed Z events.
In this investigation an energy scan around the Z peak was performed to determine
the cross sections of the Z decays in the various decay channels.
Comparison of these cross sections and the widths enabled a quantitative test of the
validity of the standard model.