Surprising Signal in Dark Matter Experiment May Indicate New Particles
An experiment searching for a mysterious substance in the universe called dark matter has picked up an unexpectedly large number of blips in the data that cannot be explained by our current models.
Led by physicists under XENON collaboration, which is a collaboration of 160 scientists from across the world who want to meddle with dark matter, this might suggest that there might be evidence of new physics -- or on a not-as-exciting note, unexpected radioactive contamination.
Researchers state that there could be three possible explanations for the blips, and while one is mundane, the other two could possibly revolutionize physics.
Engineered for the search of interactions of dark matter particles within a large vessel filled with liquid xenon, the XENON1T detector lies deep in the underground at the Gran Sasso National Laboratory in Italy.
While analyzing the newest data from the detector and looking for signs of electrons recoiling as other particles slammed into them, the researchers observed that extra recoils of electrons at low energies. This was beyond the number predicted by standard physics, with the normal interactions being around 232 electron recoils at low energy, the researchers saw 285.
According to the researchers, these blips could be due to hypothetical particles called solar axions or unexpected magnetic properties for certain known particles, neutrinos.
Or on a less interesting note, it could be a tiny amount of radioactive tritium that somehow ended up in the detector.
Assoc. Prof. Luca Grandi, a study co-author, stated, "Our data supports the solar axion hypothesis most strongly. However, if we did indeed observe solar axion interactions, the properties of the axions we observed would be in contrast with results from astrophysical observations."
As of now, it is too early to say which one it is for certain, but the researchers may be able to get a more definitive answer when the more advanced dark matter detector XENONnt becomes operational later in 2020.
The results were announced in a seminar on June 17.