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arXiv · 1909.13712

Fluctuating vector mesons in analytically continued FRG flow equations

Christopher Jung·Lorenz von Smekal
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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.

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Christopher Jung, Lorenz von Smekal. 2019-09-30. Fluctuating vector mesons in analytically continued FRG flow equations. https://doi.org/10.1103/physrevd.100.116009

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