The dominant contribution to the T’ + 47 branching ratio, coming from purely electromagnetic photon-splitting graph, is calculated. The result Br(π^0→47)≃(2.6±0.1)‧10^-11 is about three orders of magnitude below the present experimental limit.
Gorenstein, M. I., Yang, S. N., & Ko, C. M. (1992). Some Aspects of Pion Production in Heavy Ion Collisions. Chinese Journal of Physics, 30(4), 543-558. https://www.airitilibrary.com/Article/Detail?DocID=05779073-199208-201301090002-201301090002-543-558