Strange Particles in Dense Matter and Kaon Condensates

Abstract

We discuss the role of strangeness in dense matter and especially in neutron stars. The early (in density) introduction of hyperons found in many calculations is probably delayed by the decrease in vector mean field acting on the neutron. The decrease results from both conventional many-body rescattering effects and from the movement towards asymptotic freedom at high densities. Subthreshold $K^{-}$-meson production by the KaoS collaboration at GSI shows that the $K^{-}$-mass must be substantially lowered, by $\gtrsim$ 200 MeV at $\rho \sim 2{\rho }_0$. It is shown that explicit chiral symmetry breaking through the kaon mass may be responsible for ${\Sigma }^{-}$-nucleon and ${\Xi }^{-}$-nucleon scalar attraction being weaker than obtained by simple quark scaling. The normal mode of the strangeness minus, charge $e^{-}$, excitation is constructed as a linear combination of $K^{-}$-meson and ${\Sigma }^{-}$, neutron-hole state. Except for zero momentum, where the terms are unmixed the "kaesobar" is a linear combination of these two components.

10 pages, 8 postscript figures, Talk given at the International Conference on Hypernuclear and Strange Particle Physics (HYP97), Brookhaven Nat'l Lab., USA, October 13-18, 1997, to be published in Nucl. Phys. A

References in corpus (3)

• Kaons in dense matter, kaon production in heavy-ion collisions, and kaon condensation in neutron stars
• An Effective Equation of State for Dense Matter with Strangeness
• Kaon production in heavy-ion collisions and maximum mass of neutron stars

Cited by in corpus (8)

• On the uncertainty of hyperon couplings and the electrochemical potential in neutron star matter
• Microscopic three-body forces and kaon condensation in cold neutrino-trapped matter
• Nuclear Three-body Force Effect on a Kaon Condensate in Neutron Star Matter
• Static properties of chiral models with SU(3) group structure
• Kaon Condensation and Lambda-Nucleon Loop in the Relativistic Mean-Field Approach
• Nonequilibrium Weak Processes in Kaon Condensation II - Kinetics of condensation ---
• Kaonic modes in hyperonic matter and p-wave kaon condensation
• Nonequilibrium Weak Processes in Kaon Condensation I --- Reaction rate for the thermal kaon process ---