The equation of state (EoS) of QCD is a crucial input for the modeling of heavyioncollision (HIC) and neutronstarmerger systems. Calculations of the fundamental theory of QCD, which could yield the true EoS, are hindered by the infamous Fermi sign problem which only allows direct simulations at zero or imaginary baryonic chemical potential. As a direct consequence, the current coverage of the QCD phase diagram by lattice simulations is limited. In these proceedings, two different equations of state based on firstprinciple lattice QCD (LQCD) calculations are discussed. The first is solely informed by the fundamental theory by utilizing all available diagonal and nondiagonal susceptibilities up to O(µ 4 B) in order to reconstruct a full EoS at finite baryon number, electric charge and strangeness chemical potentials. For the second, we go beyond information from the lattice in order to explore the conjectured phase structure, not yet determined by LQCD methods, to assist the experimental HIC community in their search for the critical point. We incorporate critical behavior into this EoS by relying on the principle of universality classes, of which QCD belongs to the 3D Ising Model. This allows one to study the effects of a singularity on the thermodynamical quantities that make up the equation of state used for hydrodynamical simulations of HICs. Additionally, we ensure that these EoSs are valid for applications to HICs by enforcing conditions of strangeness neutrality and fixed chargetobaryonnumber ratio.
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Lattice QCD equation of state at finite chemical potential from an alternative resummation: Strangeness neutrality and beyond
In this contribution we present a resummation of the Quantum Chromodynamics (QCD) equation of state from lattice simulations at imaginary chemical potentials. We generalize the scheme introduced in a previous work [1], to the case of nonzero strangeness chemical potential. We present continuum extrapolated results for thermodynamic observables in the temperature range 130MeV ≤ T ≤ 280 MeV, for chemical potentials up to μ B / T = 3:5, along the strangeness neutral line. Furthermore, we relax the constraint of strangeness neutrality, by extrapolating to small values of the strangenesstobaryonnumber ratio R = n S / n B .
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 NSFPAR ID:
 10425259
 Editor(s):
 Kim, Y.; Moon, D.H.
 Date Published:
 Journal Name:
 EPJ Web of Conferences
 Volume:
 276
 ISSN:
 2100014X
 Page Range / eLocation ID:
 01014
 Format(s):
 Medium: X
 Sponsoring Org:
 National Science Foundation
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