Electromagnetic probes in heavy-ion collisions: Messengers from the hot and dense phase

TL;DR

Electromagnetic probes like dileptons and photons serve as essential tools to explore the hot, dense medium created in heavy-ion collisions, providing insights into QCD phase transitions and chiral symmetry restoration.

Contribution

This paper reviews the role of electromagnetic probes in revealing the properties of the hot and dense medium in heavy-ion collisions, emphasizing the importance of spectral functions and in-medium hadron resonance properties.

Findings

Electromagnetic probes penetrate dense media, providing unique insights.

Spectral properties of electromagnetic current-correlation functions are crucial.

Understanding in-medium hadron resonances aids in QCD phase diagram studies.

Abstract

Due to their penetrating nature, electromagnetic probes, i.e., lepton-antilepton pairs (dileptons) and photons are unique tools to gain insight into the nature of the hot and dense medium of strongly-interacting particles created in relativistic heavy-ion collisions, including hints to the nature of the restoration of chiral symmetry of QCD. Of particular interest are the spectral properties of the electromagnetic current-correlation function of these particles within the dense and/or hot medium. The related theoretical investigations of the in-medium properties of the involved particles in both the partonic and hadronic part of the QCD phase diagram underline the importance of a proper understanding of the properties of various hadron resonances in the medium.