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Title: Observational constraints on hyperons in neutron stars

Abstract

The possibility that neutron stars may contain substantial hyperon populations has important implications for neutron-star cooling and, through bulk viscosity, the viability of the r-modes of accreting neutron stars as sources of persistent gravitational waves. In conjunction with laboratory measurements of hypernuclei, astronomical observations were used by Glendenning and Moszkowski [Phys. Rev. Lett. 67, 2414 (1991)] to constrain the properties of hyperonic equations of state within the framework of relativistic mean-field theory. We revisit the problem, incorporating recent measurements of high neutron-star masses and a gravitational redshift. We find that only the stiffest of the relativistic hyperonic equations of state commonly used in the literature is compatible with the redshift. However, it is possible to construct stiffer equations of state within the same framework which produce the observed redshift while satisfying the experimental constraints on hypernuclei, and we do this. The stiffness parameter that most affects the redshift is not the incompressibility but rather the hyperon coupling. Nonrelativistic potential-based equations of state with hyperons are not constrained by the redshift, primarily due to a smaller stellar radius.

Authors:
; ;  [1]
  1. Center for Gravitational Wave Physics, Institute for Gravitational Physics and Geometry, Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802-6300 (United States)
Publication Date:
OSTI Identifier:
20795738
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevD.73.024021; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COSMOLOGY; COUPLING; EQUATIONS OF STATE; FLEXIBILITY; GRAVITATIONAL WAVES; HYPERNUCLEI; HYPERONS; MASS; MEAN-FIELD THEORY; NEUTRON STARS; POTENTIALS; RED SHIFT; RELATIVISTIC RANGE; VISCOSITY

Citation Formats

Lackey, Benjamin D., Nayyar, Mohit, and Owen, Benjamin J.. Observational constraints on hyperons in neutron stars. United States: N. p., 2006. Web. doi:10.1103/PHYSREVD.73.0.
Lackey, Benjamin D., Nayyar, Mohit, & Owen, Benjamin J.. Observational constraints on hyperons in neutron stars. United States. doi:10.1103/PHYSREVD.73.0.
Lackey, Benjamin D., Nayyar, Mohit, and Owen, Benjamin J.. Sun . "Observational constraints on hyperons in neutron stars". United States. doi:10.1103/PHYSREVD.73.0.
@article{osti_20795738,
title = {Observational constraints on hyperons in neutron stars},
author = {Lackey, Benjamin D. and Nayyar, Mohit and Owen, Benjamin J.},
abstractNote = {The possibility that neutron stars may contain substantial hyperon populations has important implications for neutron-star cooling and, through bulk viscosity, the viability of the r-modes of accreting neutron stars as sources of persistent gravitational waves. In conjunction with laboratory measurements of hypernuclei, astronomical observations were used by Glendenning and Moszkowski [Phys. Rev. Lett. 67, 2414 (1991)] to constrain the properties of hyperonic equations of state within the framework of relativistic mean-field theory. We revisit the problem, incorporating recent measurements of high neutron-star masses and a gravitational redshift. We find that only the stiffest of the relativistic hyperonic equations of state commonly used in the literature is compatible with the redshift. However, it is possible to construct stiffer equations of state within the same framework which produce the observed redshift while satisfying the experimental constraints on hypernuclei, and we do this. The stiffness parameter that most affects the redshift is not the incompressibility but rather the hyperon coupling. Nonrelativistic potential-based equations of state with hyperons are not constrained by the redshift, primarily due to a smaller stellar radius.},
doi = {10.1103/PHYSREVD.73.0},
journal = {Physical Review. D, Particles Fields},
number = 2,
volume = 73,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2006},
month = {Sun Jan 15 00:00:00 EST 2006}
}