Neutral pion lifetime measurements and the QCD chiral anomaly

A fundamental property of QCD is the presence of the chiral anomaly, which is the dominant component of the {\ensuremath{\pi}}^{0}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}decay rate. Based on this anomaly and its small (\ensuremath{\simeq}4.5% chiral correction, a prediction of the {\ensuremath{\pi}}^{0}lifetime can be used as a test of QCD at confinement scale energies. The interesting experimental and theoretical...