Signatures of TeV gravity from the evaporation of cosmogenic black holes

TeV gravity models provide a scenario for black hole formation at energies much smaller than G_N^(-1/2) \sim 10^19 GeV. In particular, the collision of a ultrahigh energy cosmic ray with a dark matter particle in our galactic halo or with another cosmic ray could result into a black hole of mass between 10^4 and 10^11 GeV. Once produced, such object would evaporate into elementary particles via Hawking radiation. We show that the interactions among the particles exiting the black hole are not able to produce a photosphere nor a chromosphere. We then evaluate how these particles evolve using the jet-code HERWIG, and obtain a final diffuse flux of stable 4-dimensional particles peaked at 0.2 GeV. This flux consists of an approximate 43% of neutrinos, a 28% of electrons, a 16% of photons and a 13% of protons. Emission into the bulk would range from a 1.4% of the total energy for n=2 to a 16% for n=6.