$\Delta$ (1232) effects in density-dependent relativistic Hartree-Fock theory and neutron stars

Abstract

The density-dependent relativistic Hartree-Fock (DDRHF) theory is extended to include $\Delta$-isobars for the study of dense nuclear matter and neutron stars. To this end, we solve the Rarita-Schwinger equation for spin-3/2 particle. Both the direct and exchange terms of the $\Delta$-isobars' self-energies are evaluated in details. In comparison with the relativistic mean field theory (Hartree approximation), a weaker parameter dependence is found for DDRHF. An early appearance of $\Delta$-isobars is recognized at ${\rho }_B\sim 0.27$fm${}^{-3}$, comparable with that of hyperons. Also, we find that the $\Delta$-isobars' softening of the equation of state is found to be mainly due to the reduced Fock contributions from the coupling of the isoscalar mesons, while the pion contributions are found negligibly small. We finally conclude that with typical parameter sets, neutron stars with $\Delta$-isobars in their interiors could be as heavy as the two massive pulsars whose masses are precisely measured, with slightly smaller radii than normal neutron stars.

13 pages, 7 figures, 5 tables, 4 appendixes, Phys. Rev. C (2016) accepted

References in corpus (16)

• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• Astrophysical Measurement of the Equation of State of Neutron Star Matter
• Hyperon Puzzle: Hints from Quantum Monte Carlo Calculations
• Shell Structure and $\rho$-Tensor Correlations in Density-Dependent Relativistic Hartree-Fock theory
• Spin-isospin resonances: A self-consistent covariant description
• Evolution of Nuclear Shell Structure due to the Pion Exchange Potential
• Too massive neutron stars: The role of dark matter?
• Deconfinement phase transition in hybrid neutron stars from the Brueckner theory with three-body forces and a quark model with chiral mass scaling
• Critical Density and Impact of $\Delta (1232)$ Resonance Formation in Neutron Stars
• Pseudo-spin symmetry in density-dependent relativistic Hartree-Fock theory
• Neutron stars with small radii -- the role of delta resonances
• Massive hybrid stars with a first order phase transition
• Microscopic three-body forces and kaon condensation in cold neutrino-trapped matter
• Protoneutron stars in the Brueckner-Hartree-Fock approach and finite-temperature kaon condensation
• Incoherent Neutrinoproduction of Photons and Pions in a Chiral Effective Field Theory for Nuclei

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