1. Two protons collide head on, creating a quark-gluon plasma. This decays into a shower of particles that fly off in different directions, conserving charge, spin, energy, and momentum.

2. Two protons collide head on, compressing everything far enough to create a microscopic black hole. This very quickly evaporates via Hawking radiation, creating a shower of particles that fly off in different directions, conserving charge, spin, energy, and momentum.

Could we experimentally tell the difference between scenarios 1 and 2?

3. Two protons collide head on, creating a new, unstable particle. This decays into a shower of particles that fly off in different directions, conserving charge, spin, energy, and momentum.

4. Two protons collide head on, compressing everything far enough to create a microscopic black hole. This takes a detectable amount of time before it evaporates via Hawking radiation, creating a shower of particles that fly off in different directions, conserving charge, spin, energy, and momentum.

Could we experimentally tell the difference between scenarios 3 and 4? I think the answer to this question is that yes, we could tell the difference, because if it were a black hole it would decay with a time that depends only on the mass, charge, and spin, and I don't think that unstable particles follow that pattern.