On the Four--Photon Decay of the Neutral Pion

Abstract

The dominant contribution to the ${\pi }^0\to 4\gamma$ branching ratio, coming from purely electromagnetic photon-splitting graph, is calculated. The result $Br({\pi }^0\to 4\gamma )\simeq (2.6\pm 0.1)\cdot 10^{-11}$ is about three orders of magnitude below the present experimental limit.

Comments: 6 pages, LaTeX