dr Pok Man Lo, IFT UWr

Scattering Theory Approach to the Thermodynamics of Hadrons

In this talk I shall review how the S-matrix formalism can be applied to study the thermal properties of interacting hadrons. The central idea of this approach is to compute an effective density of state from the scattering phase shifts. As the phase shifts encode a wealth of information on the hadronic interactions, e.g. the resonance widths and masses, the method can robustly handle the case of a broad resonance or a purely repulsive channel. As an application I will present an analysis on the proton yield from the heavy ion collision experiments at the LHC. I will discuss how the inconsistency between theory and experiment, the so-called proton puzzle, may be resolved by considering some essential features of the empirical baryon spectrum. These features are also crucial for understanding the Lattice results on thermal QCD, such as the baryon electric charge correlation. Lastly, I will report on some recent progress in analyzing the coupled-channel system of hyperons and the inclusion of $N>2$-body scatterings.