Fluctuating vector mesons in analytically continued FRG flow equations

Abstract

In this work we study contributions due to vector and axial-vector meson fluctuations to their in-medium spectral functions in an effective low-energy theory inspired by the gauged linear sigma model. In particular, we show how to describe these fluctuations in the effective theory by massive (axial-)vector fields in agreement with the known structure of analogous single-particle or resonance contributions to the corresponding conserved currents. The vector and axial-vector meson spectral functions are then computed by numerically solving the analytically continued functional renormalization group (aFRG) flow equations for their retarded two-point functions at finite temperature and density in the effective theory. We identify the new contributions that arise due to the (axial-)vector meson fluctuations, and assess their influence on possible signatures of a QCD critical endpoint and the restoration of chiral symmetry in thermal dilepton spectra.

18 pages, 14 figures, 2 tables

References in corpus (7)

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• In-Medium Spectral Functions of Vector- and Axial-Vector Mesons from the Functional Renormalization Group
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• Flow equations for spectral functions at finite external momenta
• Thermal Electromagnetic Radiation in Heavy-Ion Collisions
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