Speaker
Description
We present an equation of state for strongly interacting matter applicable over a broad range of temperatures and baryon densities. This is based on an effective Lagrangian with explicitly broken chiral symmetry, where scale-invariance breaking is regulated by a dilaton field that mimics the dynamics of the gluon condensate in quantum chromodynamics (QCD). The model includes baryons and mesons ($\sigma, \pi, \omega, \rho$) and incorporates thermal field fluctuations beyond mean-field approximation. Mapping the QCD phase diagram, we find a crossover associated with chiral symmetry restoration at high temperatures, consistent with lattice QCD, which turns into a first-order phase transition at high baryon densities.
We apply this EOS to the structure of neutron stars and compare the results with two distinct frameworks: an extension of the effective Lagrangian to the $SU(3)_f$ sector, and a Bayesian uncertainty quantification based on relativistic mean-field models, involving the exchange of $\sigma$, $\omega$, and $\rho$ mesons, as well as nonlinear nucleon–$\sigma$ couplings and density-dependent $\rho$ coupling. This comparison shows that the dilaton-based EOS is fully compatible with the tidal deformability inferred from GW170817 while simultaneously supporting the existence of massive neutron stars.