Speaker
Description
With the increasing richness of neutron star observations and ongoing experiments on nuclear structure, a fertile ground has emerged for exploring QCD across a wide range of densities. In our previous studies of nuclear matter properties based on a baryonic extended linear model—where the delta meson is included in the equation of state—we found that the resulting parameter space differs significantly from that of conventional Walecka-type models, in which interaction operators are often introduced for phenomenological convenience.
This discrepancy arises because the baryonic extended linear model incorporates vacuum physics, such as hadron masses generated via spontaneous chiral symmetry breaking, thereby maintaining a closer connection to QCD. In contrast, traditional approaches, particularly those focused on high-density regimes, typically neglect the underlying QCD symmetry patterns of the effective Lagrangian.
To deepen our understanding of the parameter space, we constructed a generalized Walecka-type Lagrangian that includes rho, omega, sigma, and delta mesons. All dimension-4 effective operators were systematically included without arbitrary selection. We then employed Bayesian analysis to constrain the parameter space using both neutron star observations and nuclear structure data.
Our study examined the interplay between interaction operators, nuclear matter properties, and neutron star characteristics. For example, we analyzed how the mass-radius (M-R) relation depends on key quantities such as incompressibility and the slope of the symmetry energy.