The extraordinary scientific discovery that brings us closer to the fifth force of nature

A group of scientists near the city of Chicago, in the United States, said they are about to discover the existence of a new force of nature.

They have found new evidence suggesting that subatomic particles, known as muons do not behave as predicted by current theory of subatomic physics.

Scientists believe this could indicate the existence of a hitherto unknown force acting on the muons.

More data is needed to confirm the results, but if achieved, it could mark the beginning of a new revolution in the world of physics.

All the forces that we experience in our daily lives can be classified into four categories: gravity, electromagnetism and the weak and strong nuclear forces. These four fundamental forces govern the interaction of all objects and particles throughout the universe.

accelerating muons

The discovery was made at the facilities of an American particle accelerator called Fermilab. They were working on a study Fermilab published in 2021 suggesting the possible existence of a fifth force in the universe.

Since then, the research group has collected more data and claims to have significantly reduced the uncertainty factor: “We are really testing new territory. We determine the measurements much more accurately than before.”

In an experiment with the conspicuous name “g minus two (g-2)”, the researchers accelerated subatomic particles called muons about 1000 times around a ring about 15 meters in diameterat a speed close to that of light.

The researchers found that the muons would behave in ways that cannot be explained by the existing theory, known as the Standard Model, due to the influence of a new force of nature.

While the evidence is substantial, the Fermilab team says they don’t have conclusive evidence.

Confirmation

The researchers believe they have all the information they need and that theoretical uncertainty will be reduced enough in a few years to reach their goal.

A rival team in Europe, working with the Large Hadron Collider (LHC), hopes to hit the target faster.

Mitesh Patel, of Imperial College London, is one of thousands of LHC physicists trying to find errors in the Standard Model. He told BBC News the first people to find experimental results that contradict the Standard Model would reach one of the most important milestones of all time in physics.

“Measuring behavior that doesn’t match the predictions of the Standard Model is the holy grail of particle physics. It would be the shot that starts a revolution in our understanding as the Standard Model has been confirmed through experimental testing for over 50 years.

Of Fermilab, they say their next set of results would be the “maximum encounter” between theory and experiment, which could lead to new particles or forces.

the standard model

But what is the Standard Model and why is there so much interest in experimental results that don’t really match the predictions?

Everything in our world is made up of atoms, which in turn are made up of even smaller particles.. These work together to create the four forces of nature: electricity and magnetism (electromagnetism), two nuclear forces, and gravity.

The Standard Model predicts its behavior and has been doing so perfectly, flawlessly, for 50 years..

Muons are similar to electrons, which revolve around atoms and are responsible for electric currents, but they are 200 times as massive.

In the experiment, powerful superconducting magnets were used to wobble the muons.

The results showed that the muons wobbled faster than the Standard Model should.

Professor Graziano Venanzoni, from the University of Liverpool – and one of the project’s lead researchers – told BBC News that this could be due to a new unknown force.

“We think there might be another force, something we don’t know yet, but it should be important because it tells us something new about the universe.”

If confirmed, this could be one of the most important scientific milestones of the last 100 years, since Einstein presented his theories of relativity. That’s because a fifth force, and any kind of particle associated with it, is not included in the Standard Model of particle physics.

Researchers know there is something they describe as “physics beyond the Standard Model” because current theory doesn’t fully explain everything astronomers see in space.

One of the phenomena that cannot yet be explained is the fact that galaxies are retreating faster and faster after the big bang instead of slowing down. Scientists say the acceleration is driven by an unknown force called dark energy.

Galaxies also spin much faster than they should, based on our understanding of how much material they contain. The researchers think this is caused by invisible particles called dark matter, which are not included in the Standard Model.

The results of the latest study have been published in the Magazine Physical Review Letters.