Quantum Scattering Process and Information Transfer Out of a Black Hole

We calculate the probability amplitude for tree-level elastic electron-muon scattering in Minkowski spacetime with carefully prepared initial and final wave packets. The obtained nonzero implies a nonvanishing detecting recoil electron outside light-cone of muon. Transposing this Minkowski-spacetime result to near-horizon region massive Schwarzschild black hole referring previously proposed Gedankenexperiment, we conclude that, principle, it is possible have information transfer from inside black-hole horizon outside.