High Energy Gamma Rays found from distance long Gamma Ray Bursters, are they axiphotons.

The Gamma Ray Burster, GRB 221009A Is mystery to modern physics. Observations found Gamma Rays up to 18TeV in Energy. But above 15GeV, the GZM mechanism, "R. C. Gilmore, R. S. Somerville, J. R. Primack, and A. Dominguez, Mon. Not. R. Astron. Soc. 422, 3189 (2012)." Shows that any higher energy photons would scatter of cosmic background radiation, producing pions. So what was travelling the 645 MegaParsecs from the Gamma Ray Burster if not a photon? Suggests a decaying heavy neutrino. While Looks at Axion Like Particles. Could it be a axi-photon, the vector particle associated with the a new axial force between neutrinos. I will have to see if the axi-photon scattering on cosmic background neutrinos, and any other axi-photons is suppressed at higher energies, and get back to you.