2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/42866Recent 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 data on $ϕ$-radiative decays and from $D$ decays to light hadrons is discussed. The key to further understanding is comprehensive analyses of such data, including that planned for Hall D at Jefferson Laboratory.Presented at the Workshop on Gluonic Excitations, Thomas Jefferson National Accelerator Laboratory, Newport News, May 2003High Energy Physics - Phenomenologytext