Black holes in many dimensions at the CERN large Hadron collider: Testing critical string theory

We consider black hole production at the CERN Large Hadron Collider (LHC) in a generic scenario with many extra dimensions where the standard model fields are confined to a brane. With ∼20 dimensions the hierarchy problem is shown to be naturally solved without the need for large compactification radii. We find that in such a scenario the properties of black holes can be used to determine the number of extra dimensions, n. In particular, we demonstrate that measurements of the decay distributions of such black holes at the LHC can determine if n is significantly larger than 6 or 7 with high confidence and thus can probe one of the critical properties of string theory compactifications.