QCD equation of state with improved precision from lattice simulations

¹ Dipartimento di Fisica, Università di Torino and INFN Torino, Via P. Giuria 1, I-10125 Torino, Italy
² Pennsylvania State University, Department of Physics, State College, PA 16801, USA
³ Department of Physics, Wuppertal University, Gaussstr. 20, D-42119, Wuppertal, Germany
⁴ Institute for Theoretical Physics, ELTE Eötvös Loránd University, Pázmány P. sétány 1/A, H-1117 Budapest, Hungary
⁵ Jülich Supercomputing Centre, Forschungszentrum Jülich, D-52425 Jülich, Germany
⁶ Physics Department, UCSD, San Diego, CA 92093, USA
⁷ HUN-REN-ELTE Theoretical Physics Research Group, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
⁸ Physics Department, University of Houston, Houston TX 77204, USA

^* e-mail: paolo.parotto@unito.it

Published online: 26 June 2024

Abstract

The equation of state of Quantum Chromodynamics has been in recent years the focus of intense effort from first principle methods, mostly lattice simulations, with particular interest to the finite baryon density regime. Because of the sign problem, various extrapolation methods have been used to reconstruct bulk properties of the theory up to as far as μ_B=T ≃ 3:5. However, said efforts rely on the equation of state at vanishing baryon density as an integration constant, which up to μ_B=T ≃ 2 - 2:5 proves to be the dominant source of uncertainty at the level of precision currently available. In this contribution we present the update of our equation of state at zero net baryon density from 2014, performing a continuum limit from lattices with Nτ = 8; 10; 12; 16. We show how the improved precision is translated in a lower uncertainty on the extrapolated equation of state at finite chemical potential.