Vector and Axial-Vector Mesons in Nuclear Matter

Abstract

As a first step towards a realistic phenomenological description of vector and axial-vector mesons in nuclear matter, we calculate the spectral functions of the $\rho$ and the $a_1$ meson in a chiral baryon-meson model as a low-energy effective realization of QCD, taking into account the effects of fluctuations from scalar mesons, nucleons, and vector mesons within the Functional Renormalization Group (FRG) approach. The phase diagram of the effective hadronic theory exhibits a nuclear liquid-gas phase transition as well as a chiral phase transition at a higher baryon-chemical potential. The in-medium $\rho$ and $a_1$ spectral functions are calculated by using the previously introduced analytically-continued FRG (aFRG) method. Our results show strong modifications of the spectral functions in particular near the critical endpoints of both phase transitions which may well be of relevance for electromagnetic rates in heavy-ion collisions or neutrino emissivities in neutron-star merger events.

16 pages, 10 figures

References in corpus (9)

• Exact evolution equation for the effective potential
• Renormalization Group Approach towards the QCD Phase Diagram
• Cold, dense nuclear matter in a SU(2) parity doublet model
• In-Medium Spectral Functions of Vector- and Axial-Vector Mesons from the Functional Renormalization Group
• Nuclear Matter and Neutron stars in a Parity Doublet Model
• Symmetries of hadrons after unbreaking the chiral symmetry
• An effective model for the QCD phase transitions at finite baryon density
• Flow equations for spectral functions at finite external momenta
• Fluctuating vector mesons in analytically continued FRG flow equations

Cited by in corpus (14)

• Impact of pions on binary neutron star mergers
• Real-time methods for spectral functions
• From quarks and gluons to color superconductivity at supranuclear densities
• Fluctuations near the liquid-gas and chiral phase transitions in hadronic matter
• Speed of sound in dense strong-interaction matter
• Self-consistent $O(4)$ model spectral functions from analytically continued FRG flows
• Fluctuations and correlations of baryonic chiral partners
• Regulator scheme dependence of the chiral phase transition at high densities
• Effects of chiral symmetry restoration on meson and dilepton production in relativistic heavy-ion collisions
• Effective spectral function of vector mesons via lifetime analysis
• Spectral function of the ${\eta }^{\prime }$ meson in nuclear medium based on phenomenological models
• Constituent quark axial current couplings to light vector mesons in the vacuum and with a weak magnetic field
• Polarization of Thermal Dilepton Radiation
• Renormalization-Group Invariant Parity-Doublet Model for Nuclear and Neutron-Star Matter