Scientists testing whether Einstein’s theory of relativity holds under extreme conditions have found no evidence against one of its key principles in an initial analysis of neutrinos detected beneath the Mediterranean Sea. The findings are based on 5,828 atmospheric neutrinos recorded by KM3NeT/ORCA.
Lorentz invariance is the principle that the laws of physics are the same in every direction. Some researchers have proposed that it could break down under extreme conditions. Neutrinos offer a way to test the idea because they can travel through space with very little interaction with matter, and their changes between three types, or flavours, follow precise predictions.
ORCA is located 2,450 metres below the sea off the coast of Toulon, France. Neutrinos are difficult to detect, but when one interacts with matter in the water, it can produce charged particles that emit blue light. Instruments can detect that light and use it to identify neutrino properties.
The study analysed 1.4 years of data from the detector’s first six units. The researchers report that the results match predictions for neutrino behaviour and reach a level of precision comparable to that of established experiments such as IceCube in Antarctica and Super-Kamiokande in Japan.
The KM3NeT project also includes ARCA, a detector 3,500 metres deep off the coast of Sicily. While ORCA focuses on lower-energy atmospheric neutrinos, ARCA is designed to study higher-energy neutrinos from deep space. The researchers plan to examine neutrino oscillations there, where possible departures from Lorentz invariance could be more pronounced. The ORCA results are only an initial part of the investigation.
Sources: Xataka.