2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/133132Recent work in light flavour hadron physics is reviewed. In particular, I discuss the significance of the progress achieved with light dynamical quarks on the lattice for the effective low energy theory of QCD. Also, I draw attention to some puzzling results from NA48 and KTeV concerning the scalar form factor relevant for Kmu3 decay -- taken at face value, these indicate physics beyond the Standard Model.Contribution to the proceedings of the Rencontres de Moriond on QCD and Hadronic Interactions, La Thuile, Italy, March 2007; added references, minor changes in the textHigh Energy Physics - PhenomenologyInsights and puzzles in light quark physicstext