The (what very much feels like an) assertion that "If a collision concentrates enough energy in a small enough region, the particles form a black hole" seems ve

The (what very much feels like an) assertion that "If a collision concentrates enough energy in a small enough region, the particles form a black hole" seems very much rabbit out of a hat. That supposes in particular that general relativity is still a valid theory at these minuscule scales, something that I believe has never been experimentally verified. If general relativity's equations do not work at the planck scale, we know strictly nothing about black hole formation.