The η→π0γγ decay amplitude is discussed in the general context of chiral perturbation theory assuming that the low-energy constants (counterterms) are saturated by the known meson resonances. The suppression of the lowest order contributions is understood in physical terms. A reasonable agreement with the experimental decay width is achieved. © 1992.
|Journal||Physics Letters B|
|Publication status||Published - 6 Feb 1992|