1201.6486 (Hyun Kyu Lee et al.)

Flavor Symmetry and Nuclear Symmetry Energy for Compact Stars    [PDF]

Hyun Kyu Lee, Mannque Rho

The nuclear symmetry energy figures crucially in the structure of asymmetric
nuclei and, more importantly, in the equation of state (EoS) of compact stars.
At present it is almost totally unknown, both experimentally and theoretically,
in the density regime appropriate for the interior of neutron stars. Based on a
strong-coupled structure of dense baryonic matter encoded in the skyrmion
crystal approach and resorting to the notion of generalized hidden local
symmetry in hadronic interactions, we address a variety of hitherto unexplored
issues of nuclear interactions associated with the symmetry energy, namely, the
role of flavor symmetry such as kaon condensation and hyperons, nuclear tensor
forces, the manifestation of conformal symmetry and chiral symmetry in the EoS
of dense compact-star matter etc. One of the surprising results coming from the
hidden local symmetry structure is the discovery that at high density, the
strong short-range repulsion described in terms of $\omega$-meson exchanges get
suppressed by the flow to the dilaton-limit fixed point constrained by "mended
symmetries." We further propose how to formulate the role of kaon condensation
and the role of hyperons in compact-star matter in a unified framework by
treating hyperons as the Callan-Klebanov kaon-skyrmion bound states simulated
on crystal lattice and suggest that hyperons come in the star-matter {\em when}
kaons condense. In our simplified description of the stellar structure in terms
of symmetry energies which is compatible with that of the 1.97 solar mass star,
kaon condensation plays a role of "doorway state" to strange-quark matter.

View original: http://arxiv.org/abs/1201.6486