dr Pasi Huovinen

The hunt for (almost) perfect fluid

The fundamental building blocks of matter, quarks and gluons, are always confined to form hadrons. However, we expect that in extremely large temperatures and densities this confinement would be broken and quarks and gluons would move freely forming so called quark matter or quark-gluon plasma. It is believed that such a state of matter did exist a few milliseconds after the big bang, and that it has been recreated in ultrarelativistic heavy-ion collisions of large nuclei in the experiments at Brookhaven National Laboratory and CERN. It looks like that the matter created in these collisions has extraordinary properties like such a low kinematic viscosity that it has been described as perfect fluid. In this talk I will describe how we have come to believe that quark-gluon plasma has been created in the heavy-ion collisions, and our attempts to evaluate its hydrodynamical properties.