Scientists researching dark matter have finally found evidence for axions, previously a hypothetical non-light emitting particle that explains how subatomic particles behave. The presence of axions was first proposed in the 1970s to resolve asymmetries in the strong force that holds quarks together. 

The signals were detected in the XENON1T experiment based in Italy, where the insulated xenon tanks emitted flashes. The flashes do not necessarily prove the existence of axions - they can also occur because of interaction with other particles, such as tritium. 

Luca Grandi, one of the leading researchers in the experiment, said, “Despite being excited about this excess, we should be very patient.” 

Another explanation for the flashes could also be neutrinos, which might have large magnetic moments, making them scatter electrons at a high rate and causing the flashes. Or, the flashes may have come from contamination. An experiment to rule out the contamination is set to begin soon.

‍

‍

Chanda Prescod-Weinstein, a physicist at the University of New Hampshire who isn’t a part of the research team said, “If this bears out, and ‘if’ is a big question, this is the biggest game-changer in my corner of physics since the discovery of cosmic acceleration.”

If the discovery is confirmed, the breakthrough results would answer a major unknown of the universe. Peter Graham, a particle physicist at Stanford University said, “Such an axion could also be produced in the early universe and then would make up some component of dark matter.”

The XENON1T experiment is a trailblazer in the search for answers about dark matter, initially started to explore WIMPS- weakly interacting massive particles, thought to have been left over after the Big Bang.