Relativistic Heavy Ion Collisions: Viscous Hydrodynamic Simulations and Final State Interactions

Relativistic Heavy Ion Collisions: Viscous Hydrodynamic Simulations and Final State Interactions Matthew W. Luzum Chair of the Supervisory Committee: Professor Gerald A. Miller Department of Physics In this dissertation I introduce relativistic heavy ion collisions and describe theoretical approaches to understanding them—in particular, viscous hydrodynamic simulations and investigations of final state interactions. The successful ideal hydrodynamic models of the collisions at the Relativistic Heavy Ion Collider (RHIC) were extended by performing viscous hydrodynamic simulations. This was done by making use of the recently derived full conformally invariant second order relativistic viscous hydrodynamic equations. Results for multiplicity, radial flow and elliptic flow in √ sNN = 200 GeV Au+Au RHIC collisions are presented and the range of the ratio of shear viscosity over entropy density ηs for which our hydrodynamic model is consistent with experimental data is quoted. In addition, simulations were performed of the planned √ sNN = 5.5 TeV Pb+Pb and √ s = 14 TeV p+p collisions at the Large Hadron Collider (LHC). The elliptic flow coefficient v2 is predicted to be 10% larger for the Pb+Pb collisions compared to top energy RHIC collisions, and is predicted to be consistent with zero for proton collisions unless ηs < 0.08. Finally, final state interactions were investigated within the distorted wave emission function (DWEF) model. Work is presented on an improved understanding of the DWEF model, and the potential effect of final state interactions in the form of a pion optical potential on the elliptic flow coefficient v2 was calculated to be at the ∼ 20% level.