On the miracle of the Coleman-Glashow and other baryon mass formulas
  Due to a new measurement of the Xi(0) mass,the Coleman-Glashow formula for the baryon octet e.m. masses (derived using unbroken SU(3) 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 parameterization method. 
G.Dillon and G.Morpurgo (Universita` di Genova and Istituto Nazionale   di Fisica nucleare,Genova,Italy)