Higher energy particles may form black holes.

Evidence

If one had a particle with an energy above what is called the Planck energy, ten million million million GeV (1 followed by nineteen zeros), its mass would be so concentrated that it would cut itself off from the rest of the universe and form a little black hole. — Hawking, Stephen, A Brief History of Time, 328

Categorization

• corroborated: 2 independent passages support this claim — Hawking, Stephen, A Brief History of Time, 328