Abstract
Corrections to the Wess–Zumino–Witten anomaly caused by the explicit breaking of the $$SU(3) \times SU(3)$$ chiral symmetry are studied using the effective meson Lagrangian based on the Nambu–Jona-Lasinio model with the simultaneous expansion in derivatives, current quark masses, and 1/Nc powers. The leading contribution and the first correction for the amplitudes of the π0, η, η' → γγ decays and the contact term in the $$\eta {\text{/}}\eta {\kern 1pt} ' \to {{\pi }^{ + }}{{\pi }^{ - }}\gamma $$ amplitudes have been calculated. The results are compared with similar 1/Nc chiral perturbation calculations and existing experimental data.
Subject
Physics and Astronomy (miscellaneous)