Selection rules for inclusive reactions

Assuming quark model and the hypothesis of limiting fragmentation, selection rules are obtained for inclusive reactions. It predicts dσ(PP → P + anything) ⪢ dσ(PP → π^± + anything, K⁺ + anything) ⪢⪢dσ(PP→K−+anything,P+anything) role=presentation style=font-size: 90%; display: inline-block; position: relative;>$\text{⪢}\text{d}\text{σ(}\text{PP}\text{→}\text{K}{}^{\mathrm{-}}\text{+}\text{anything,}\text{P}\text{+}\text{anything}\text{)}$$\text{⪢}\text{d}\text{σ(}\text{PP}\text{→}\text{K}{}^{\mathrm{-}}\text{+}\text{anything,}\text{P}\text{+}\text{anything}\text{)}$ in agreement with experiments.