An unprecedented empirical rule for the baryon and meson mass spectra

An empirical rule, previously proposed for ground-state baryons and the only meson K, is widely extended to mesons. The rule maps pairs of hadrons (h(1), h(2)), or single hadrons hl' onto single higher-lying hadrons H. The mapping law requires that if a certain partial sum of a given power series equals the sum of the masses of hadrons h, then the whole series converges to the mass of a hadron H.