# Two-Flavor Staggered Fermion Thermodynamics at N_t = 12

## TL;DR

This study investigates the high temperature crossover in two-flavor QCD using staggered fermions at a very fine lattice spacing, analyzing critical behavior, susceptibilities, and the equation of state to understand chiral symmetry restoration.

## Contribution

It provides new results at the smallest lattice spacing to date and compares QCD critical behavior with O(4) and mean field models across multiple lattice sizes.

## Key findings

- Determined the QCD crossover temperature with high precision.
- Analyzed the chiral order parameter and susceptibilities for critical behavior.
- Compared the QCD equation of state with spin model predictions.

## Abstract

We present results of an ongoing study of the nature of the high temperature crossover in QCD with two light fermion flavors. These results are obtained with the conventional staggered fermion action at the smallest lattice spacing to date---approximately 0.1 fm. Of particular interest are a study of the temperature of the crossover a determination of the induced baryon charge and baryon susceptibility, the scalar susceptibility, and the chiral order parameter, used to test models of critical behavior associated with chiral symmetry restoration. From our new data and published results for N_t = 4, 6, and 8, we determine the QCD magnetic equation of state from the chiral order parameter using O(4) and mean field critical exponents and compare it with the corresponding equation of state obtained from an O(4) spin model and mean field theory. We also present a scaling analysis of the Polyakov loop, suggesting a temperature dependent ``constituent quark free energy.''