Dark Photon-Photon Resonance Conversion of GRB221009A through Extra Dimension

Abstract: The recently observed very high energy (VHE) photons dubbed as GRB221009A by several terrestrial observatories such as LHAASO and Carpet-2 require a physics explanation beyond the standard model. Such energetic gamma ray bursts, originating from yet unknown very distance source at redshift z = 0.1505, would be directly scattererd by extragalactic background lights (EBL) rendering its improbable detection at the earth. We show that dark photon which resides in extra dimension would be able to resolve this issue when it oscillates resonantly with the photon in similar fashion with neutrino oscillation. We demonstrate that, for dark photon mass equals to 1 eV, the probability of GRB221009A photons with energy above 0.2 TeV to reach the earth lies in the range between $10^{-6} \, \text{to} \, 95\% $ for kinetic mixing values $10^{-14} \leq \epsilon \leq 10^{-12.5}$ allowed by current constraints.