Dipl.-Phys. Niels-Uwe Bastian, IFT UWr

Phenomenology of the QCD phase transition

Even half a century after the introduction of the quark model, their behaviour is barely understood. Ab initio calculations of QCD, the theory of strongly interacting matter, are only accessible at vanishing chemical potentials. The rest of the QCD phase diagram is under heavy debate, which is the topic of astrophysics and modern heavy-ion collision experiments. In particular, the possible appearance of a phase transition of first-order from ordinary nuclear matter to the so-called quark-gluon plasma is a matter of many speculations. In the first part of my presentation, I will present our research on the detectability of such phase transitions in astrophysics. It turns out, that the mass-radius measurement of neutron stars, the gravitational wave signal of binary neutron star mergers as well as the neutrino signal of supernova explosions might produce detectable signals in case of a first-order phase transition. The second part will address the formulation of thermodynamics of strongly-interacting matter. I will present two newly developed formalisms which are together capable to describe even complex interactions as confinement and treat hadrons as bound states of quarks. These features lead me to the final goal to formulate a unified description of the entire quark-hadron phase diagram.