Stellar Structure and Stability of Charged Interacting Quark Stars and
  Their Scaling Behaviour
We explore the stellar structure and radial stability of charged quark stars
composed of interacting quark matter (IQM) in three classes of commonly used
charge models. We adopt a general parametrization of IQM equation of state that
includes the corrections from perturbative QCD, color superconductivity, and
the strange quark mass into one parameter $\lambda$, or one dimensionless
parameter $\bar{\lambda}=\lambda^2/(4B_{\rm eff})$ after being rescaled with
the effective bag constant $B_{\rm eff}$. We find that increasing charge tends
to increase the mass and radius profiles, and enlarges the separation size in
mass between the maximum mass point and the point where zero eigenfrequencies
$\omega^2_0=0$ of the fundamental radial oscillation mode occur. The sign of
the separation in central density depends on the charge model; this separation
also has a dependence on $\lambda$ such that increasing $\lambda$ (which can
occur for either large color superconductivity or small strange quark mass)
tends to decrease this separation size for the first and third classes of
charge models monotonically. Moreover, for the second and third classes of
charge models, we manage to numerically and analytically identify a new kind of
stellar structure with a zero central pressure but a finite radius and mass.
All the calculations and analysis are performed in a general dimensionless
rescaling approach so that the results are independent of explicit values of
dimensional parameters.
Chen Zhang Michael Gammon Robert B. Mann