Mass formula for strange and nonstrange quark matter

A mass formula for spherical lumps of two- and three-flavor quark matter is derived self-consistently from an asymptotic expansion within the MIT bag model, taking into account bulk, surface, curvature, and Coulomb contributions. For massless quarks the asymptotic expansion fits exceedingly well with exact mode-filling calculations. A bulk approximation to the mass formula is also discussed. The curvature energy is extremely important, adding up to $400A^{-\frac{2}{3}}$ MeV to the energy per baryon for baryon number $A$.