On the miracle of the Coleman–Glashow and other baryon mass formulas

Due to a new measurement of the Ξ0 mass, the Coleman–Glashow formula for the baryon octet e.m. masses (derived using unbroken flavor SU3) is satisfied to an extraordinary level of precision. The same unexpected precision exists for the Gell Mann–Okubo formula and for its octet-decuplet extension (G. Morpurgo, Phys. Rev. Lett. 68 (1992) 139). We show that the old question “why do they work so well?” is now answered by the general parametrization method.