Hadron masses and the sigma commutator in light of chiral perturbation theory

We analyze carefully the impact of non-analytic chiral corrections to the mass spectrum of the pseudoscalar meson octet J/sup p/ = 0- and the baryon octet J/sup p/ = 1/2+. We find that the quark mass ratios must lie in the range 21< or =m/sub s//m< or =32 and 1.6< or =m/sub d//m/sub u/< or =2.2. We also calculate the anogalous corrections to the pion-nucleon sigma commutator sigma/sub piN/. It turns out that the value sigma/sub piN/ = 60 MeV is not compatible with the structure of the meson and baryon spectrum, unless the nucleon mass is smaller than 600 MeV in the chiral limit m/sub u/ = m/sub d/ = m/sub s/ = 0