Luca Bonanno, Armen Sedrakian
The recent measurement of a $1.97\pm 0.04$ solar-mass pulsar places a
stringent lower bound on the maximum mass of compact stars and therefore
challenges the existence of any agents that soften the equation of state of
ultra-dense matter. We investigate whether hyperons and/or quark matter can be
accommodated in massive compact stars by constructing an equation of state
based on a combination of phenomenological relativistic hyper-nuclear density
functional and an effective model of quantum chromodynamics (the
Nambu-Jona-Lasinio model). Stable configurations are obtained with $M \ge 1.97
M_{\sun}$ featuring hyper-nuclear and quark matter in color superconducting
state if the equation of state of nuclear matter is stiff above the saturation
density, the transition to quark matter takes place at a few times the nuclear
saturation density, and the repulsive vector interactions in quark matter are
substantial.
View original:
http://arxiv.org/abs/1108.0559
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