On the four-photon decay of the neutral pion
Bratkovskaya E. L. , Kuraev E. A., Silagadze Z. K.
The dominant contribution to the π —>4γ branching ratio, coming from the purely electromagnetic photon-splitting graph, is calculated. The result fir(7r°—>4-y)~(2.6±0.1)ž 10~u is about three orders of magnitude below the present experimental limit. © 1995 American Institute of Physics.