Chiral Dynamics: New Experimental Tests

Wednesday 8 Apr 2009, 15:00 → 16:30 Europe/Rome

Auditorium B. Touschek (Laboratori Nazionali di Frascati, Via Enrico Fermi 40, Frascati)

ABSTRACT

This talk will survey the current status of low energy scattering and electromagnetic production experiments of the pi-meson. These experiments test predictions based on spontaneous chiral symmetry breaking in QCD. In addition a new precise measurement of the lifetime of the neutral pi meson into two gamma rays will be presented. This decay amplitude is dominated by the axial anomaly of QCD, modified by a small chiral correction which is proportional to the mass difference of the up and down quarks. The status of some other tests of this dynamic isospin breaking mechanism will be discussed.