Hadron properties in the nuclear medium

TL;DR

This paper reviews theoretical predictions and experimental efforts to observe changes in hadron properties within hot and dense nuclear media, focusing on chiral symmetry restoration effects on mesons.

Contribution

It provides a comprehensive overview of the theoretical expectations and experimental status regarding in-medium hadron spectra related to chiral symmetry restoration.

Findings

In-medium modifications of meson properties are consistent with partial chiral symmetry restoration.

Experimental data suggest observable changes in meson spectra in nuclear matter.

Theoretical models predict specific shifts in hadron masses and widths in dense environments.

Abstract

The QCD vacuum shows the dynamical breaking of chiral symmetry. In the hot/dense QCD medium, the chiral order parameter such as $ < \bar q q > $ is expected to change as function of temperature $T$ and density $\rho$ of the medium, and its experimental detection is one of the main challenges in modern hadron physics. In this article, we discuss theoretical expectations for the in-medium hadron spectra associated with partial restoration of chiral symmetry and the current status of experiments with an emphasis on the measurements of properties of mesons produced in near-ground-state nuclei.