Thermal dilepton rates and in-medium hadron properties from lattice QCD

TL;DR

This paper reviews recent lattice QCD studies on thermal hadron properties and dilepton production, highlighting methods to reconstruct spectral functions and analyze medium modifications near the deconfinement transition.

Contribution

It demonstrates the use of the Maximum Entropy Method to reconstruct spectral functions without prior assumptions and applies it to study in-medium hadron modifications and dilepton rates.

Findings

Reconstructed spectral functions reveal medium modifications of hadrons.

Thermal dilepton production rates can be extracted from vector meson spectral functions.

In-medium hadron properties change significantly near the deconfinement transition.

Abstract

Recent progress of lattice investigations in thermal physics is summarized in this contribution. Hadronic spectral functions can be reconstructed from correlation functions in Euclidean time based on the Maximum Entropy Method without a priori assumptions on the spectral shape. The thermal modifications of hadron properties are investigated in the scalar, pseudo-scalar, vector and axial-vector channels near and above the deconfinement transition temperature for charmonium systems as well as for light quarks. Moreover, the reconstructed vector meson spectral function allows to extract the thermal cross section for the production of dilepton pairs at vanishing momentum.