Insights and puzzles in light quark physics

Abstract

Recent 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.

Comments: 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 text