ORCA Tests Einstein Principle With 5,828 Neutrinos, Finds No Lorentz Violations
Updated
Updated · Livescience.com · Nov 5
ORCA Tests Einstein Principle With 5,828 Neutrinos, Finds No Lorentz Violations
3 articles · Updated · Livescience.com · Nov 5
Summary
Data from 5,828 atmospheric neutrinos collected over 17 months in 2020-21 showed no deviation from Lorentz invariance, a core assumption shared by relativity and the Standard Model.
ORCA made the test with its first six deep-sea detection units off Toulon, tracking neutrinos that traveled up to 12,700 kilometers through Earth, where any violation should have altered their oscillation pattern.
The result sets competitive limits despite ORCA's partial buildout and includes the first direct constraints on violations that would affect muon and tau neutrinos differently.
Those bounds already rival results from larger experiments such as Super-Kamiokande and IceCube, while ORCA has expanded to 44 units and aims for 108 by 2030.
Researchers next plan to use ORCA's sister detector ARCA off Sicily to probe higher-energy cosmic neutrinos, which could offer even more sensitive tests of space-time structure.