Effect of vector--axial-vector mixing to dilepton spectrum

TL;DR

This paper investigates how vector--axial-vector meson mixing affects the dilepton spectrum in hot and dense matter, revealing significant modifications such as broadening and enhancement of the spectral function.

Contribution

It provides a detailed analysis of vector--axial-vector mixing effects on the dilepton spectrum in hot and dense environments, including new interaction mechanisms.

Findings

Axial-vector meson significantly influences the vector spectral function in hot matter.

Mixing in dense baryonic matter causes broadening of the vector spectrum.

Enhancement of the spectral function occurs below the rho meson mass for small momenta.

Abstract

In this write-up we summarize main results of our recent analyses on the mixing between transverse rho and a1 mesons in hot and/or dense matter. We show that the axial-vector meson contributes significantly to the vector spectral function in hot matter through the mixing. In dense baryonic matter, we include a mixing through a set of omega rho a1 -type interactions. We show that a clear enhancement of the vector spectral function appears below \sqrt{s}=m_\rho for small three-momenta of the rho meson, and thus the vector spectrum exhibits broadening.