# Conserved charge fluctuations at vanishing and non-vanishing chemical potential

## TL;DR

This paper computes high-order cumulants of conserved charge fluctuations in lattice QCD to understand the transition from hadronic matter to quark-gluon plasma, highlighting deviations from the hadron resonance gas model at various chemical potentials.

## Contribution

It provides detailed lattice QCD calculations of cumulants up to sixth order, extending understanding of conserved charge fluctuations at finite chemical potential.

## Key findings

- Significant differences between QCD and HRG model at T > 155 MeV
- Deviations increase with non-zero baryon chemical potential
- Constraints on HRG applicability range at higher chemical potentials

## Abstract

Up to 6th order cumulants of fluctuations of net baryon-number, net electric charge and net strangeness as well as correlations among these conserved charge fluctuations are now being calculated in lattice QCD. These cumulants provide a wealth of information on the properties of strong-interaction matter in the transition region from the low temperature hadronic phase to the quark-gluon plasma phase. They can be used to quantify deviations from hadron resonance gas (HRG) model calculations which frequently are used to determine thermal conditions realized in heavy ion collision experiments. Already some second order cumulants like the correlations between net baryon-number and net strangeness or net electric charge differ significantly at temperatures above 155 MeV in QCD and HRG model calculations. We show that these differences increase at non-zero baryon chemical potential constraining the applicability range of HRG model calculations to even smaller values of the temperature.