Scientists explain how a 300 TeV photon could reach Earth
2 hours ago
- GRB 221009A emitted a powerful gamma-ray burst on 9 October 2022, detected by LHAASO and Carpet, with a 300 TeV photon-like event that defies standard physics predictions.
- Background light, especially the cosmic microwave background (CMB), makes the universe opaque to 300 TeV photons via pair production, with conventional models predicting only ~10^-96 expected photons.
- Two hypothetical effects are proposed: axion-like particles (ALPs) can explain LHAASO's lower-energy photons but fail at 300 TeV, while Lorentz invariance violation (LIV) can explain the 300 TeV photon but not lower energies.
- A combined framework of ALPs and LIV accounts for observations across both energy ranges, with LIV modifying photon absorption thresholds using higher-energy background photons.
- Time delay between LHAASO and Carpet events supports quadratic LIV, with consistent energy scales, but a single candidate photon cannot confirm new physics.
- Future observatories (ASTRI, CTAO, SWGO, LHAASO) may provide further tests for similar high-energy signatures from gamma-ray bursts and active galaxies.