In-medium spectral functions of vector- and axial-vector mesons from the functional renormalization group

Abstract:

In this work, we present the first results on vector- and axial-vector meson spectral functions as obtained by applying the nonperturbative functional renormalization group approach to an effective low-energy theory motivated by the gauged linear sigma model. By using a recently proposed analytic continuation method, we study the in-medium behavior of the spectral functions of the ρ and a₁ mesons in different regimes of the phase diagram. In particular, we demonstrate explicitly how these spectral functions degenerate at high temperatures as well as at large chemical potentials, as a consequence of the restoration of chiral symmetry. In addition, we also compute the momentum dependence of the ρ and a₁ spectral functions and discuss the various timelike and spacelike processes that can occur.

C. Jung, F. Rennecke, R.-A. Tripolt, L. von Smekal, J. Wambach: In-medium spectral functions of vector- and axial-vector mesons from the functional renormalization group, Phys. Rev. D 95 (2017) 036020

https://doi.org/10.1103/PhysRevD.95.036020

Related to Project C06