Seminar in Hadronic Physics

Constraining the QCD Equation of State at High Temperatures Using Heavy-Ion Collisions

Evan Warren Sangaline

Michigan State University

The experimental determination of the nuclear equation of state of super-hadronic matter has been a longstanding goal in the field of nuclear physics. We address this objective through the comparison of experimental results from the Large Hadron Collider and the Relativistic Heavy Ion Collider to those produced by a hydrodynamic-based transport model. The theoretical model is used to train a Gaussian process emulator which very closely approximates the dependence of experimental observables on the parameters in a high dimensional parameter space. Using the emulator in place of the model allows us to reduce the computational requirements sufficiently to make possible rigorous statistical inferences within a Bayesian framework using a Markov chain Monte Carlo method. We employ this methodology to constrain both the equation of state and the energy dependence of the shear viscosity of nuclear matter at temperatures above 165 MeV while simultaneously allowing for broad uncertainties in the modeling of the initial state.