Science Daily May 2, 2024
If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. A team of researchers from several countries used atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5–10.0 TeV to search for coherence loss in neutrino propagation. They found no evidence of anomalous neutrino decoherence and determined limits on neutrino–quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improved on previous limits by a factor of 30. For decoherence effects scaling as E2, their limits were advanced by more than six orders of magnitude beyond past measurements compared with the state of the art… read more. TECHNICAL ARTICLE
Illustration of the quantum gravitational decoherence effect. Credit: Nature Physics, 26 March 2024