Vector and axial-vector mesons at nonzero temperature within a gauged linear sigma model

Abstract

We consider vector and axial-vector mesons in the framework of a gauged linear sigma model with chiral $U({N}_{f}{)}_{R}\ifmmode\times\else\texttimes\fi{}U({N}_{f}{)}_{L}$ symmetry. For ${N}_{f}=2$, we investigate the behavior of the chiral condensate and the meson masses as a function of temperature by solving a system of coupled Dyson-Schwinger equations derived via the 2PI formalism in double-bubble approximation. We find that the inclusion of vector and axial-vector mesons tends to sharpen the chiral transition. Within our approximation scheme, the mass of the $\ensuremath{\rho}$ meson increases by about 100 MeV towards the chiral transition.