Classicalizing theories are characterized by a rapid growth of the scattering
cross section. This growth converts these sort of theories in interesting
probes for ultra-high energy experiments even at relatively low luminosity,
such as cosmic rays or Plasma Wakefield accelerators. The microscopic reason
behind this growth is the production of N-particle states, classicalons, that
represent self-sustained lumps of soft Bosons. For spin-2 theories this is the
quantum portrait of what in the classical limit are known as black holes. We
emphasize the importance of this quantum picture which liberates us from the
artifacts of the classical geometric limit and allows to scan a much wider
landscape of experimentally-interesting quantum theories. We identify a
phenomenologically-viable class of spin-2 theories for which the growth of
classicalon production cross section can be as efficient as to compete with QCD
cross section already at 100 TeV energy, signaling production of quantum black
holes with graviton occupation number of order 10^4.Comment: 23 pages, late
