Equilibrium and Transport Properties of the Hot and Dense Matter Created in High Energy Nuclear Collisions

Abstract

As a postdoctoral researcher at USP, I will implement viscous corrections into the hydrodynamical code known as SPHERIO developed by the Sao Paulo - Rio de Janeiro group. This is an ideal hydrodynamical code defined in 3+1 dimensions that can run event by event. Once this viscous version of SPHERIO is completed, I intend to incorporate the temperature dependent transport coefficients $\eta$ and $\zeta$ in the hadronic phase including Hagedorn states (highly massive resonances that follow an exponentially increasing mass spectrum) that I computed in my Ph.D thesis, as well as the corresponding lattice estimates above $T_c$. A realistic lattice-based equation of state for the QGP will be used in the simulations. This whole effort will lead to the first 3+1-dimensional viscous hydro code (with the combined effects of bulk and shear viscosities) that can be efficiently run event by event. Using this new version of SPHERIO, we will be able to perform state-of-the-art calculations that will determine how the temperature dependence of the transport coefficients, which so far has been vastly neglected in relativistic hydrodynamic simulations, may affect key signatures of QGP formation computed in an event-by-event basis such as the elliptic flow of hadrons.Additionally, I will also continue the research on Hagedorn states that I started in my Ph.D thesis. One interesting question that I will explore is how the specific form of the hadron mass spectrum affects important quantities needed in the description of a hadronic gas such as its transport coefficients. Moreover, how does the choice in our mass spectrum affect the reactions themselves, do binary reactions or multi-particle decays dominate? Hagedorn states can further be explored by studying more exotic states such as multi-strange baryons. Thus, using a canonical model or other theories currently discussed today in spectroscopy, we could describe these strange and/or baryonic Hagedorn states and see how they populate resonances such as $\Omega$'s. Furthermore, I want to extend my previous research towards different regions of the QCD phase diagram, for instance, to low temperatures and large baryon chemical potentials near the putative QCD critical point.