Using idealized models of the accretion disk, we investigate effects induced by modified theories gravity on annihilation neutrino pair into electron-positron pairs ($\nu{\bar \nu}\to e^-e^+$), occurring near rotational axis. For have considered with temperature $T=constant$ and $T\propto r^{-1}$. In both cases, find that lead to an enhancement, up more than one order magnitude respect General ...