On the fluid behavior of a baryon rich hadron resonance gas

TL;DR

This paper studies how finite baryon chemical potential influences the fluid-like behavior of a hadron resonance gas, suggesting that higher baryon density systems at RHIC behave more like an ideal fluid, explaining similar flow measurements across energies.

Contribution

It demonstrates that a baryon-rich hadron resonance gas exhibits fluid properties closer to an ideal fluid than a baryon-free gas, especially at lower collision energies.

Findings

Baryon-rich gas approaches ideal fluid behavior.

Lower energy collisions at RHIC show similar elliptic flow to higher energies.

Finite baryon chemical potential enhances fluidity of the hadron gas.

Abstract

We investigate the effects of finite baryon chemical potential on the transport properties of a hadron resonance gas. We find that a hadron resonance gas with large baryon number density is closer to the ideal fluid limit than the corresponding gas with zero baryon number. This suggests that the system created at the Relativistic Heavy Ion Collider (RHIC) at lower collision energies may behave as a fluid, with an effective fluidity close to the one found at RHIC's highest energy near phase transition. This might explain why the differential elliptic flow coefficient measured at lower collisional energies at RHIC is similar to the one observed at high energies.