Conserved charge fluctuations at vanishing net-baryon density from Lattice QCD

TL;DR

This paper provides continuum-extrapolated lattice QCD results for second-order cumulants at zero net-baryon density, comparing them with hadron resonance gas models and virial expansion to assess their applicability.

Contribution

It offers the first continuum-extrapolated lattice QCD results for all second-order cumulants at vanishing baryon density and evaluates HRG model assumptions against these results.

Findings

Lattice QCD results constrain HRG model spectra.

Comparison shows HRG models with repulsive interactions align with lattice data.

Results inform the validity of HRG models at zero baryon density.

Abstract

We present here continuum extrapolated results for all 2nd order cumulants using the most recent results obtained by the HotQCD collaboration in (2+1)-flavor QCD. We constrain the applicability of various HRG models by presenting a detailed comparison of our results based on different sets of hadron spectra as well as with virial expansion based model calculations. A comparison with our lattice QCD results for 2nd order cumulants with models that parametrize repulsive interactions among baryons and anti-baryons in a hadron resonance gas through a single excluded volume parameter (EVHRG) is also shown.