Scientists say ‘fifth force of nature’ possible after latest discovery

the Muon g-2 magnetic ring at Fermilab in Chicago
Researchers used the Muon g-2 magnetic ring at Fermilab in Chicago to conduct the test - Ryan Postel/PA Wire

Scientists believe they could be nearing the discovery of a new fifth force of nature.

It came after an experiment confirmed the peculiar wobble of a subatomic particle called a muon.

The findings suggest scientists may be missing something in their current understanding of physics, perhaps some unknown particle or force.

Muons are fundamental particles, similar to electrons, that orbit an atom’s nucleus, but they are more than 200 times heavier.

On Thursday, researchers announced the results of an experiment at the US Energy Department’s Fermilab facility in Illinois.

The experiment studied muons as they moved through a magnetic field at nearly the speed of light.

Muons, like electrons, have a tiny internal magnet that causes them to wobble.

The speed of the wobble in the experiment varied considerably from what was predicted, suggesting it was affected by a mysterious factor.

A previous experiment in 2021 similarly showed an anomalous wobble.

The new results were based on quadruple the amount of data, bolstering confidence in the findings.

‘New features of space-time’

Brendan Casey, a senior scientist at Fermilab said: “We are looking for an indication that the muon is interacting with something that we do not know about.

“It could be anything – new particles, new forces, new dimensions, new features of space-time, anything.”

Rebecca Chislett, a University College London physicist and co-author of the study, said: “Yes, it is fair to say that it could be pointing to unknown particles or forces.

“With all this new knowledge the result still agrees with the previous results, and this is hugely exciting.”

The experiment was conducted at minus 450 degrees Fahrenheit.

The researchers shot beams of muons into a doughnut-shaped superconducting magnetic storage ring measuring 50ft in diameter.

A research paper on the findings was published in the journal Physical Review Letters.