Properties of the phi meson at high temperatures and densities

TL;DR

This paper investigates how the spectral density of the phi meson changes in hot, dense nuclear matter, revealing a slight peak shift and significant broadening at high temperatures and densities.

Contribution

It introduces a comprehensive method combining experimental data and Regge parameterization to analyze the phi meson spectral density in hot, dense environments.

Findings

Peak of spectral density slightly shifts from vacuum position

Width of spectral density increases significantly at high temperature and density

Width exceeds 90 MeV at 150 MeV temperature and normal nuclear density

Abstract

We calculate the spectral density of the phi meson in a hot bath of nucleons and pions using a general formalism relating self-energy to the forward scattering amplitude (FSA). In order to describe the low energy FSA, we use experimental data along with a background term. For the high energy FSA, a Regge parameterization is employed. We verify the resulting FSA using dispersion techniques. We find that the position of the peak of the spectral density is slightly shifted from its vacuum position and that its width is considerably increased. The width of the spectral density at a temperature of 150 MeV and at normal nuclear density is more than 90 MeV.