In the debris of hadron interactions lies the beauty of QCD (part II)

Abstract

Recent progress in understanding the strong physics regime of QCD is described. The role played by condensates, particularly $<q{\bar q} >$, in breaking chiral symmetry and generating constituent masses for $u$ and $d$ quarks is reviewed. The influence this has on hadrons with vacuum quantum numbers is emphasised. What we know of this sector from recent experiments on $\phi$-radiative decays and from $D$ decays to light hadrons is discussed. How we may gain a more complete understanding of this vacuum sector is outlined.