Finite Temperature Lattice QCD with Wilson Quarks
Theoretical investigation of matter at extreme high temperatures and densities has a huge importance since this kind of matter is produced in heavy-ion collision experiments: e.g. in the ALICE experiment of the recently started Large Hadron Collider. Providing a firm theoretical basis for such experiments is essential. The main tool for these investigations was invented by Nobel-prize laureate Kenneth Wilson in the early 70's (Wilson's lattice QCD). Soon alternative approaches have been proposed, one of them turned out to be very popular (staggered lattice QCD), since it is much less demanding in terms of computer time. But it lacks the solid foundations, which Wilson's original approach has.
In this project a team of scientists from the Bergische Universität Wuppertal (Theoretische Teilchenphysik, Fachbereich C) compared some properties of the extreme hot matter using these two approaches: the cheaper staggered formulation and the rigorous but more expensive Wilson formulation. A nice agreement has been found, lending support to many other existing calculations with the staggered approach.
Chiral condensate as a function of the temperature calculated using the staggered approach (blue) and Wilson's approach (red). The temperature scale at the bottom axis is given relative to the mass of the omega particle, while at the top it is given in MeV's. 1 MeV is equal to approximately 1.16 * 10^10 Kelvin.
Dr. Kálmán Szabó
Theoretische Physik, Fachbereich C - Bergische Universität Wuppertal