**Fig. (1)** (Color on line). Scanned insert from Fig. (**6**) of [**5**] showing the scatter plot of the two photon invariant mass *M(γ*_{3}γ_{4}) (in MeV),
versus the two photon invariant mass *M(γ*_{1}γ_{2}) (in MeV). The areas surrounded by red squares correspond to the narrow weakly excited
low mass unflavored mesons highlighted in this work. The three blue circled areas correspond to *M(γγ)* ≈ 743 MeV (see text). Reprinted
figure with permission from Claude Amsler, Reviews of Modern Physics, Vol. 70, 1293 (1998).