What is the 5th force of nature, investigated by scientists – 08/10/2023 – Science

All the forces we experience every day can be reduced to just four categories: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force.

These four fundamental forces govern how all objects and particles in the universe interact with one another.

The discoveries were made at a US particle accelerator facility called Fermilab.

They build on results announced in 2021, in which the Fermilab team first hinted at the possibility of a fifth force of nature.

Since then, the research team has gathered more data and reduced the uncertainty of their measurements by a factor of two, according to Brendan Casey, senior scientist at Fermilab.

“We are really exploring new territory. We are determining [as medidas] with better accuracy than ever.”

In an experiment called “g minus two (g-2)”, the researchers accelerate subatomic particles called muons around a ring 15 meters in diameter, where they circulate about a thousand times at almost the speed of light.

The researchers discovered that these particles may be behaving in a way that cannot be explained by the current theory, called the Standard Model, because of the influence of a “new force” of nature.

While the evidence is strong, the Fermilab team has yet to come up with conclusive proof.

They had hoped to get them now, but uncertainties about the standard model of the amount of oscillation in muons have increased due to developments in theoretical physics.

In essence, it’s as if the goalposts have been moved for the experimental physicists.

The researchers believe they will have the data they need and that the theoretical uncertainty will have diminished enough within two years for them to reach their goal.

That said, a rival team at the Large Hadron Collider (LHC) in Europe is hoping to get to those results first.

Scientist Mitesh Patel of Imperial College London is among the LHC physicists trying to find flaws in the Standard Model.

He told BBC News that finding experimental results at odds with the Standard Model would be one of the greatest advances in physics.

“Measuring behavior that doesn’t agree with the Standard Model’s predictions is the holy grail for particle physics. It would trigger a revolution in our understanding, because the model has withstood all experimental tests for over 50 years,” he says. the scientist.

Fermilab says its next set of results will be “the ultimate showdown” between theory and experiment that could reveal new particles or forces.

So what is the Standard Model and why is getting an experimental result that doesn’t fit your predictions so important?

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

Its behavior is predicted by the standard model, and for 50 years it has predicted its behavior perfectly, without a single error.

Muons are similar to the electrons that orbit atoms and are responsible for electrical currents, but they are about 200 times more massive.

In the experiment, they were made to oscillate using powerful superconducting magnets.

The results showed that the muons oscillated faster than the standard model predicted. Professor Graziano Venanzoni of the University of Liverpool, who is one of the lead researchers on the project, told BBC News that this could be caused by an unknown new force.

“We think there may be another force, something we don’t know about now. It’s something different, which we call the ‘fifth force’. It’s something we don’t know yet, but it must be important, because it says something new about the universe”, he explains.

If confirmed, this would undoubtedly represent one of the greatest scientific advances in the last 100 years since Albert Einstein’s theories of relativity. This is because a fifth force and any particles associated with it are not part of the Standard Model of particle physics.

Researchers know that there is what they describe as “physics beyond the Standard Model” out there, because current theory cannot explain many things astronomers observe in space.

This includes the fact that galaxies continue to accelerate after the Big Bang that created the universe, rather than slowing down in expansion. Scientists say the acceleration is being driven by an unknown force called dark energy.

Galaxies are also rotating faster than they should, according to our understanding of how much matter is in them. The researchers believe this is because of invisible particles called dark matter, which again are not part of the Standard Model.

The results were published in the Journal Physical Review Letters.

This text was originally published here.