Behavior of Hadrons at Finite Density -- Lattice Study of Color SU(2) QCD

TL;DR

This lattice QCD study explores how hadron properties, especially vector mesons, change at high baryon densities in two-color QCD, revealing a novel reduction in vector meson mass at large chemical potential.

Contribution

First lattice QCD analysis showing vector meson mass reduction at high density in two-color QCD with Wilson fermions.

Findings

Vector meson propagators are significantly modified at high chemical potential.

First observation of vector meson mass reduction in lattice QCD.

Thermodynamical quantities vary with chemical potential and hopping parameter.

Abstract

Using two-color lattice QCD with Wilson fermions, we report a study of the finite baryon number density system with two-flavors. First we investigate the Polyakov line and thermodynamical uantities in the $(\kappa,\mu)$ plane, where $\kappa$ and $\mu$ are the hopping parameter and chemical potential in the fermion action, respectively. Then we calculate propagators of meson ($\bar{q}\Gamma q$) and baryon ($q\Gamma q$) states. We find that the vector meson propagators are strongly modified in large $\mu$ regions, indicating the reduction of the mass. This anomalous behavior of the vector meson is observed for the first time in lattice QCD.