Equation of state of strongly magnetized matter with hyperons and $\Delta$-resonances

TL;DR

This paper develops a new equation of state for strongly magnetized baryonic matter including hyperons and $\Delta$-resonances, revealing magnetic field effects on neutron star properties and matter composition.

Contribution

It extends covariant density functional theory to include hyperons and $\Delta$-resonances under strong magnetic fields, constrained by hypernuclear data.

Findings

Magnetic fields stiffen the equation of state, increasing neutron star maximum mass.

Strangeness fraction in matter is enhanced by magnetic fields.

Oscillatory behavior in observables due to Landau level occupation patterns.

Abstract

We construct a new equation of state for the baryonic matter under an intense magnetic field within the framework of covariant density functional theory. The composition of matter includes hyperons as well as $ \Delta$-resonances. The extension of the nucleonic functional to the hypernuclear sector is constrained by the experimental data on $\Lambda$ and $\Xi$-hypernuclei. We find that the equation of state stiffens with the inclusion of the magnetic field, which increases the maximum mass of neutron star compared to the non-magnetic case. In addition, the strangeness fraction in the matter is enhanced. Several observables, like the Dirac effective mass, particle abundances, etc show typical oscillatory behavior as a function of the magnetic field and/or density which is traced back to the occupation pattern of Landau levels.