Hybrid RBRC seminar

Abstract: Cumulants of conserved charge fluctuations probe the thermal state of strongly interacting matter and have been the focus of many studies, both theoretical and experimental, in recent years. In lattice QCD calculations, they allow access to bulk thermodynamic quantities at small, non-vanishing chemical potential via Taylor expansion and find application in the search for a critical endpoint in the QCD phase diagram. Furthermore, they can serve as benchmark observables for
constraining the range of validity of widely used hadron resonance gas models.

Over the last years, the HotQCD collaboration has gathered high statistics data on cumulants of conserved charge fluctuations from
lattice QCD simulations using the HISQ discretization scheme for staggered fermions with 2+1 flavors. This talk aims to provide an
overview of recent results obtained using this data.

Specifically, precise continuum extrapolations for the six second order cumulants of conserved charge fluctuations and their correlations are presented and compared to various non-interacting, point-like hadron resonance gas models. Furthermore, I present updated results on pressure, energy density and entropy density calculations at non-zero chemical potentials using up to 8th order Taylor expansions. I discuss estimators of the radius of convergence for these expansions and construct Padé approximants for the pressure at non-zero values of the baryon chemical potential.