Equation of state of a hot-and-dense quark gluon plasma: Lattice simulations at real μ_B vs. extrapolations

¹ Department of Physics, Wuppertal University, Gaussstr. 20, D-42119, Wuppertal, Germany
² Pennsylvania State University, Department of Physics, State College, Pennsylvania 16801, USA
³ Jülih Supercomputing Centre, Forschungszentrum Jülich, D-52425 Jülich, Germany
⁴ ELTE Eötvös Loránd University, Institute for Theoretical Physics, Pázmány Péter sétány 1/A, H-1117, Budapest, Hungary
⁵ HUN-REN-ELTE Theoretical Physics Research Group, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
⁶ Physics Department, UCSD, San Diego, CA 92093, USA

Published online: 26 June 2024

Abstract

The equation of state of the quark gluon plasma is a key ingredient of heavy ion phenomenology. In addition to the traditional Taylor method, several novel approximation schemes have been proposed with the aim of calculating it at finite baryon density. In order to gain a pragmatic understanding of the limits of these schemes, we compare them to direct results at μ_B > 0, using reweighting techniques free from an overlap problem. We use 2stout improved staggered fermions with 8 time-slices and cover the entire RHIC BES range in the baryochemical potential, up to μ_B/T = 3. This work is based on Ref. [1].