# QCD equation of state at finite baryon density with fugacity expansion

## TL;DR

This paper develops a model for the QCD equation of state at finite baryon density using lattice data and fugacity expansion, enabling improved simulations of heavy-ion collisions.

## Contribution

It introduces a crossover model based on the cluster expansion model fitted to lattice QCD data for finite baryon density.

## Key findings

- Accurate description of lattice data at imaginary and zero chemical potential.
- A parameterized pressure function for finite baryon density.
- Application potential in fluid dynamical simulations of heavy-ion collisions.

## Abstract

We explore the QCD equation of state at finite baryon density through an expansion in baryon number fugacity, making use of the recent lattice data on the four leading Fourier coefficients of the expansion. A state-of-the-art description of the lattice data at both imaginary $\mu_B$ and $\mu_B = 0$ is provided by the cluster expansion model (CEM). The CEM pressure function has three temperature dependent input parameters, which we fix by parameterizing the available lattice QCD data. This results in a crossover model of the QCD equation of state at finite baryon density, which can be used in fluid dynamical simulations of heavy-ion collisions.