Hawking evaporation of cosmogenic black holes in TeV-gravity models

TL;DR

This paper investigates the evaporation of cosmogenic black holes in TeV-scale gravity models, analyzing particle emission spectra and the absence of chromosphere formation during Hawking radiation.

Contribution

It provides the first detailed spectrum analysis of particles emitted from black holes in TeV-gravity models, considering various extra dimensions and black hole masses.

Findings

Particle spectra peak around 0.2 GeV with specific composition ratios.

No chromosphere formation occurs during Hawking evaporation.

Bulk gravitons constitute a small fraction of emitted particles.

Abstract

We study the properties of black holes of mass 10^4--10^{11} GeV in models with the fundamental scale of gravity at the TeV. These black holes could be produced in the collision of a ultrahigh energy cosmic ray with a dark matter particle in our galactic halo or with another cosmic ray. We show that QCD bremsstrahlung and pair production processes are unable to thermalize the particles exiting the black hole, so a chromosphere is never formed during Hawking evaporation. We evaluate with HERWIG the spectrum of stable 4-dim particles emitted during the Schwarzschild phase and find that in all cases it is peaked at energies around 0.2 GeV, with an approximate 43% of neutrinos, 28% of photons, 16% of electrons and 13% of protons. Bulk gravitons are peaked at higher energies, they account for a 0.4% of the particles (16% of the total energy) emitted by the most massive black holes in n=6 extra dimensions or just the 0.02% of the particles (1.4% of the energy) emitted by a 10 TeV black hole for n=2.