(ORDO NEWS) — After a decade of careful measurements, scientists announced on Thursday that a fundamental particle — the W boson — has a much larger mass than thought, shaking the foundations of our understanding of how the universe works.
These foundations are laid down in the Standard Model of particle physics, which is the best theory scientists have for describing the most basic building blocks of the universe and what forces govern them.
The W boson governs the so-called weak force, one of the four fundamental forces of nature, and is therefore the basis of the Standard Model.
However, a new study published in the journal Science says that the most accurate measurement ever made of the W boson directly contradicts the model’s predictions.
Ashutosh Kotwal, the Duke University physicist who led the study, told AFP that the result took more than 400 scientists over 10 years to scrutinize four million W boson candidates from a “dataset of about 450 trillion collisions.”
These collisions, which cause particles to collide with each other at mind-boggling speeds, were conducted at the Tevatron Collider in the US state of Illinois to study them.
It was the world‘s highest-energy particle accelerator until 2009, when it was superseded by the Large Hadron Collider near Geneva, where the Higgs boson was discovered a few years later.
The Tevatron went out of business in 2011, but scientists at the Fermilab Collider Detector (CDF) have been counting the numbers ever since.
Harry Cliff, a particle physicist at the University of Cambridge working at the Large Hadron Collider, said the Standard Model is “probably the most successful scientific theory ever written down.”
“It can make fantastically accurate predictions,” he said. But if those predictions turn out to be wrong, the model can’t just be tweaked.
“It’s like a house of cards: if you pull too hard on one part of it, the whole thing collapses,” Cliff told AFP.
The Standard Model is not without .
For example, it does not take into account dark matter, which, together with dark energy, makes up 95 percent of the universe. She also argues that the universe should not have existed from the beginning because the Big Bang should have annihilated itself.
In addition, “several cracks” were recently discovered in this model, the physicists said in an accompanying article in Science.
“In this system of hints that there are missing parts in the standard model, we have added another very interesting and somewhat big hint,” said Kotwal.
Jan Stark, physicist and director of research at France‘s CNRS institute, said “this is either a major discovery or a problem in data analysis,” predicting “quite heated discussions in the coming years.”
He told AFP that “unusual claims require extraordinary evidence.”
CDF scientists said they have determined the mass of the W boson to within 0.01 percent – twice as accurate as previous attempts.
They compared this to measuring the weight of a 350-kilogram (800-pound) gorilla to within 40 grams (1.5 ounces).
They found that the boson differed from the standard model’s predictions by seven standard deviations, also called sigma.
Cliff said that if you were tossing a coin, “the odds of getting a five-sigma result are, by sheer luck, one in three and a half million.”
“If this is indeed the case, and not some systematic error or misunderstanding of how to do the calculations, then this is very important, because it means that there is a new fundamental component in our Universe that we have not yet discovered,” he said. .
“But if you’re going to say something as important as that we’ve broken the standard model of particle physics, and there are new particles that need to be discovered to convince people of that, you’ll probably need more than one dimension out of more than one experiment.”
CDF co-chair David Toback said “it is now up to the theoretical physics community and other experiments to follow this and shed light on this mystery.”
And after a decade of measurements, Kotval hasn’t finished yet.
“We’re following the clues and leaving no stone unturned, so we’ll find out what that means.”
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.