2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/51679Particles colliding at impact parameter much larger than the effective gravitational radius can not classically form a black hole and just scatter off the radial potential barrier separating the particles. We show that the process of the black hole production can still go quantum-mechanically via familiar mechanism of the under-barrier tunneling. The mechanism is illustrated for collision of a trans-Planckian particle and a lighter particle. Our analysis reveals instability of trans-Planckian particles against transition to the phase of black hole.Talk presented at the 3rd Sakharov International Conference on Physics, Moscow, June 2002; to appear in the proceedings of the conferenceHigh Energy Physics - Theorytext