Fluctuations at finite temperature and density

TL;DR

This paper reviews lattice calculations of conserved charge fluctuations at finite temperature and density, highlighting their relevance to heavy ion collision experiments and theoretical extrapolations.

Contribution

It provides a comprehensive review of recent lattice results on charge fluctuations and discusses their implications for phenomenology and perturbation theory.

Findings

Lattice calculations of charge fluctuations are consistent with experimental data.

Finite density effects can be extrapolated from zero density results using derivatives of free energy.

Implications for heavy ion collision phenomenology are discussed.

Abstract

Fluctuations of conserved charges in a grand canonical ensemble can be calculated as derivatives of the free energy with respect to the respective chemical potential. They are directly related to experimentally available observables that describe the hadronization in heavy ion collisions. The same derivatives can be used to extrapolate zero density results to finite chemical potential. We review the recent lattice calculations in the staggered formalism and discuss its implications to phenomenology and resummed perturbation theory.