Strange Quark Matter Densities Compared with the Up- and Down-Quark Branches of the Bound

If strange quark matter is the true ground state of dense matter, self-bound quark stars could exist with central densities modestly above nuclear saturation and surfaces at nearly constant density. Because their spin carriers would be quarks rather than nucleons, the operative density bound for such objects sits on the quark branches. This paper computes those branches, 5.33e+49 g per cubic centimetre for up quarks and 2.43e+50 g per cubic centimetre for down quarks, and compares quark-star densities from 4e17 to 2e18 kg per cubic metre against them. At 1e18 kg per cubic metre the attained fractions are 1.88e-35 of the up branch and 4.11e-36 of the down branch, and a uniform 1.4-solar-mass star at that density has a radius of 8.727e+00 km. Even the lightest confined carriers in the densest proposed stars leave the bound remote. Simulated from stated assumptions, not measured.