Current Algebra and theη→π+π−π0γ

Chiral perturbation theory predictions for η → π+π−π0γ

“…The same conclusion was reached long ago by Singer [3] in his VMD calculation, as well as in the more detailed CA analysis of ref. [4], where A (IB) was predicted to be larger than A (SD) only for photon energies E γ ≤ 15 MeV, well below its maximum value E max γ ≃ 120 MeV. These two and other old theoretical calculations for A (SD) (based on CA and/or VMD) [3,4,5]…”

“…[4], where A (IB) was predicted to be larger than A (SD) only for photon energies E γ ≤ 15 MeV, well below its maximum value E max γ ≃ 120 MeV. These two and other old theoretical calculations for A (SD) (based on CA and/or VMD) [3,4,5] lead to…”

“…This is a useful conclusion in that it contradicts (and presumably corrects) older results (see refs. [4], [3]) and it will furnish a clear-cut test for (and presumably confirm) ChPT. But it is also a deceptive conclusion reducing most of the η → π + π − π 0 γ dynamics to that of η → π + π − π 0 , already studied both theoretically [1] and experimentally [7] (although not free of uncertainties [1,18,21]).…”