The implications of gamma-ray photons from LHAASO on Lorentz symmetry

TL;DR

This paper analyzes high-energy gamma-ray data from LHAASO to assess potential Lorentz symmetry violations, finding that current observations do not strongly suggest such violations at PeV energies.

Contribution

It provides a detailed calculation of gamma-ray survival probabilities considering Lorentz symmetry, offering constraints on possible violations at ultra-high energies.

Findings

Gamma-ray photons up to 1.42 PeV detected by LHAASO.

Survival probability of photons remains high (~0.60), indicating no strong evidence for Lorentz violation.

Current data does not conclusively prove Lorentz symmetry violation at PeV energies.

Abstract

The Large High Altitude Air Shower Observatory (LHAASO) has reported the measurement of photons with high energy up to 1.42 PeV from twelve gamma-ray sources. We are concerned with the implications of LHAASO data on the fate of Lorenz symmetry at such high energy level, thus we consider the interaction of the gamma ray with those photons in cosmic microwave background (CMB), and compute the optical depth, the mean free path as well as the survival probability for photons from all these gamma-ray sources. Employing the threshold value predicted by the standard special relativity, it is found that the lowest survival probability for observed gamma ray photons is about 0.60, which is a fairly high value and implies that abundant photons with energy above the threshold value may reach the Earth without Lorentz symmetry violation. We conclude that it is still far to argue that the Lorentz symmetry would be violated due to the present observations from LHAASO.