Effects of the U-boson on the inner edge of neutron star crusts

Abstract

We explore effects of the light vector $U$-boson, which is weakly coupled to nucleons, on the transition density ${\rho }_t$ and pressure $P_t$ at the inner edge separating the liquid core from the solid crust of neutron stars. Three methods, i.e., the thermodynamical approach, the curvature matrix approach and the Vlasov equation approach are used to determine the transition density ${\rho }_t$ with the Skyrme effective nucleon-nucleon interactions. We find that the ${\rho }_t$ and $P_t$ depend on not only the ratio of coupling strength to mass squared of the $U$-boson $g^2/{\mu }^2$ but also its mass $\mu$ due to the finite range interaction from the $U$-boson exchange. In particular, our results indicate that the ${\rho }_t$ and $P_t$ are sensitive to both $g^2/{\mu }^2$ and $\mu$ if the $U$-boson mass $\mu$ is larger than about 2 MeV. Furthermore, we show that both $g^2/{\mu }^2$ and $\mu$ can have significant influence on the mass-radius relation and the crustal fraction of total moment of inertia of neutron stars. In addition, we study the exchange term contribution of the $U$-boson based on the density matrix expansion method, and demonstrate that the exchange term effects on the nuclear matter equation of state as well as the ${\rho }_t$ and $P_t$ are generally negligible.

16 pages, 8 figures. Fig. 1 and Fig. 4 revised, typos fixed. Published version in PRD

References in corpus (34)

• Shapiro delay measurement of a two solar mass neutron star
• Neutron Star Observations: Prognosis for Equation of State Constraints
• Tests of the Gravitational Inverse-Square Law below the Dark-Energy Length Scale
• Nuclear symmetry energy probed by neutron skin thickness of nuclei
• U-boson production in e+e- annihilations, psi and Upsilon decays, and Light Dark Matter
• Isotopic dependence of the giant monopole resonance in the even-A ^{112-124}Sn isotopes and the asymmetry term in nuclear incompressibility
• Maximum elastic deformations of compact stars with exotic equations of state
• Symmetry energy from elliptic flow in 197Au + 197Au
• Core-crust transition in neutron stars: predictivity of density developments
• Systematics of pion emission in heavy ion collisions in the 1A GeV regime
• Neutron skin thickness in droplet model with surface width dependence: indications of softness of the nuclear symmetry energy
• The symmetry energy at subnuclear densities and nuclei in neutron star crusts
• Neutron scattering and extra short range interactions
• Nuclear symmetry energy and its density slope at normal density extracted from global nucleon optical potentials
• Isospin-dependent clusterization of Neutron-Star Matter
• Locating the inner edge of neutron star crust using terrestrial nuclear laboratory data
• Accurate Measurement in the Field of the Earth of the General-Relativistic Precession of the LAGEOS II Pericenter and New Constraints on Non-Newtonian Gravity
• The nuclear symmetry energy and stability of matter in neutron star
• The Giant Monopole Resonance in the Sn Isotopes: Why is Tin so "Fluffy"?
• Nuclear symmetry energy and core-crust transition in neutron stars: a critical study
• Nuclear matter symmetry energy and the symmetry energy coefficient in the mass formula
• The Neutron Star Crust: Nuclear Physics Input
• Constraints on new interactions from neutron scattering experiments
• Cluster formation in compact stars: relativistic versus Skyrme models
• Cluster formation in asymmetric nuclear matter: semi-classical and quantal approaches
• Higher order bulk characteristic parameters of asymmetric nuclear matter
• Bounds on new light particles from high-energy and very small momentum transfer np elastic scattering data
• U-boson at BESIII
• Effects of a weakly interacting light U boson on the nuclear equation of state and properties of neutron stars in relativistic models
• U-boson and the HyperCP exotic events
• Density matrix expansion for the MDI interaction
• Dynamical properties of nuclear and stellar matter and the symmetry energy
• Constraints, limits and extensions for nuclear energy functionals
• Proposal for an experiment to search for Randall-Sundrum type corrections to Newton's law of gravitation

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• Nuclear constraints on non-Newtonian gravity at femtometer scale
• Old neutron stars as probes of isospin-violating dark matter
• Equation of state and hybrid star properties with the weakly interacting light U-boson in relativistic models
• The restriction of ${\sigma }^{\ast }$ and $\varphi$ on the protoneutron stars PSR J0348+0432
• Influence of the weakly interacting light U boson on the properties of massive PNS
• Non-Newtonian gravity in finite nuclei