The role of instantons in quantum chromodynamics: (II). Hadronic structure

The “constituent quark” (or “valon”) substructure of ordinary hadrons is the consequence of small instanton radius $\text{?}{}_{\mathrm{<mtext>c</mtext>}}\text{?}\text{1}\text{3}\text{fm}$ in the QCD vacuum. The same parameter determines hadronic masses and other parameters, in particular the unusually large mass scale for “exceptional” hadrons with zero spin.