Measurement of the pi0 Lifetime: QCD Axial Anomaly and Chiral Symmetry
Aula Seminari (LNF INFN)
Via Enrico Fermi, 40
A brief history of the measurements of the pi0 lifetime will be presented, highlighted by a new Primakoff effect measurement with an accuracy of 3%. This tests a prediction due to the axial anomaly of QCD, modified by a small isospin breaking chiral correction which is proportional to the mass difference of the up and down quarks. The implications of this result for future experimental tests of the axial anomaly will be discussed, with emphasis on the possibilities at Frascati.