Emission from accelerated protons and electrons/positrons in the BdHN paradigm.

We present the study of the high-energy photon emission by protons and electrons/positrons accelerated by an electric field of a Kerr black hole (BH) in an overcritical magnetic field. Protons can reach energies up to $\sim 10^{21}$ eV. The principal process is synchrotron emission. We calculate the photon emission probability and opacity in order to see whether these photons can escape from the BH site, accounting for the different energies emission detected from GRBs observations. The escaping probability is dictated by the multiple interactions of $e^{+}/p/\gamma$ and EM cascade processes. We calculate all the cross-sections and mean free paths for each process and estimate the total optical depth.