The $\rho$ meson in hot hadron matter and low mass dilepton spectra

TL;DR

This paper analyzes the $ ho$ meson’s spectral function in hot hadronic matter using thermal field theory, revealing enhanced dilepton production and proposing effective temperature as a phase indicator.

Contribution

It provides a detailed analysis of the $ ho$ meson self-energy in hot matter and introduces the use of effective temperature from dilepton spectra to characterize different phases.

Findings

Enhanced dilepton production below the $ ho$ peak in hot matter.

Effective temperature from transverse momentum spectra can distinguish phases.

Spectral function modifications reflect medium effects on the $ ho$ meson.

Abstract

The structure of the one loop self-energy graphs of the $\rho$ meson is analyzed in the real time formulation of thermal field theory. The modified spectral function of the $\rho$ meson in hot hadronic matter leads to a large enhancement of lepton pair production below the bare peak of the $\rho$. It has been shown that the effective temperature extracted from the inverse slope of the transverse momentum distributions for various invariant mass ($M$) windows of the pair can be used as an efficient tool to characterize different phases of the evolving matter.