Heavy-Ion physics at the CERN accelerator complex

(WA93, WA98 and Alice experiments, CERN Geneva and Utrecht 1991-2003).

The goal of this research is to study the fundamental building blocks of nuclear matter

(i.e. quarks and gluons) under extremely high densities and temperatures.

These extreme conditions are achieved by collisions of highly energetic heavy nuclei.

Hereby one expects to whitness the onset of thermalisation or a phase transition from

ordinary nuclear matter into a deconfined phase, the so-called Quark-Gluon Plasma (QGP),

predicted by the theoretical model describing the strong interaction.

It is expected that such a QGP state existed in the early Universe, only several microseconds

after the Big Bang.

After having played a coordinating role in the physics feasibility studies and construction

of an overal software framework for the various experiments, my efforts focused on a

measurement of direct photon production.

This was performed by a new method which I had devised myself.

The aim was to detect thermal radiation of the formed system and investigate

the initial conditions and system evolution, based on the observed photon spectra.

Application of this new method on the available data shows indeed a possible

signal of thermal radiation.