Spin Polarization Effects in Micro Black Hole Evaporation

TL;DR

This paper investigates how the rotation of micro black holes affects their evaporation, revealing polarization effects and spectral deviations that could help determine black hole properties and rotation axes.

Contribution

It introduces the analysis of polarization and angular distribution effects in rotating micro black hole evaporation, proposing methods to determine rotation axes and distinguish effects from extra dimensions.

Findings

Rotation causes helicity-dependent angular distributions.

Rapid rotation increases the effective temperature, altering the spectrum.

Angular distribution analysis can help identify black hole rotation parameters.

Abstract

We consider the evaporation of rotating micro black holes produced in highly energetic particle collisions, taking into account the polarization due to the coupling between the spin of the emitted particles and the angular momentum of the black hole. The effect of rotation shows up in the helicity dependent angular distribution significantly. By using this effect, there is a possibility to determine the axis of rotation for each black hole formed, suggesting a way to improve the statistics. Deviation from thermal spectrum is also a signature of rotation. This deviation is due to the fact that rapidly rotating holes have an effective temperature $T_{\rm eff}$ significantly higher than the Hawking temperature $T_H$. The deformation of the spectral shape becomes evident only for very rapidly rotating cases. We show that, since the spectrum follows a blackbody profile with an effective temperature, it is difficult to determine both the number of extra-dimensions and the rotation parameter from the energy spectrum alone. We argue that the helicity dependent angular distribution may provide a way to resolve this degeneracy. We illustrate the above results for the case of fermions.