AUGER-HiRes results and models of Lorentz symmetry violation

TL;DR

This paper analyzes how AUGER and HiRes cosmic-ray data impact models of Lorentz symmetry violation, discussing implications for fundamental physics, potential new particles like superbradyons, and the need for space-based tests of relativity.

Contribution

It evaluates the constraints that high-energy cosmic-ray observations place on Lorentz symmetry violation models and explores the potential role of superbradyons as dark matter candidates.

Findings

Data can exclude some LSV models and parameters.

Unconventional LSV effects may mimic the GZK cutoff.

Superbradyons could be new constituents of matter and dark energy.

Abstract

The implications of AUGER and HiRes results for patterns of Lorentz symmetry violation (LSV) are examined, focusing on weak doubly special relativity (WDSR). If the Greisen-Zatsepin-Kuzmin (GZK) cutoff is definitely confirmed, the mass composition of the highest-energy cosmic-ray spectrum will be a crucial issue to draw precise theoretical consequences from the experimental results. Assuming that the observed flux suppression is due to the GZK mechanism, data will allow in principle to exclude a significant range of LSV models and parameters, but other important possibilities are expected to remain open : Lorentz breaking can be weaker or occur at a scale higher than the Planck scale, unconventional LSV effects can fake the GZK cutoff, threshold phenomena can delay its appearance... Space experiments appear to be needed to further test special relativity. We also examine the consequences of AUGER and HiRes data for superbradyons. If such superluminal ultimate constituents of matter exist in our Universe, they may provide new forms of dark matter and dark energy.