# TNT Colloquium: Effect of the QCD equation of state on flow observables in heavy ion collisions[Duke]

#### Tuesday, January 16, 2018 - 3:30pm

The QCD equation of state at zero baryon chemical potential is the only element of the standard dynamical framework to describe heavy ion collisions that can be directly determined from first principles. Continuum extrapolated lattice QCD equations of state have been computed using 2+1 quark flavors (up/down and strange) as well as 2+1+1 flavors to investigate the effect of thermalized charm quarks on QCD thermodynamics. Lattice results have also indicated the presence of new strange resonances that not only contribute to the equation of state of QCD matter but also affect hadronic afterburners used to model the later stages of heavy ion collisions. We investigate how these new developments obtained from first principles calculations affect multiparticle correlations in heavy ion collisions. Using an outdated equation of state can directly affect the extraction of the shear viscosity to entropy density ratio of the quark-gluon plasma and results for different flow observables. In this talk, results are shown for RHIC AuAu 200 GeV, LHC PbPb 5.02 TeV, and LHC XeXe 5.44 TeV collisions.