‘Tantalizing’ results of 2 experiments defy physics rulebook

Preliminary results from two experiments recommend one thing could possibly be mistaken with the fundamental manner physicists suppose the universe works, a prospect that has the sphere of particle physics each baffled and thrilled.

Tiny particles referred to as muons aren’t fairly doing what is anticipated of them in two completely different long-running experiments within the United States and Europe. The confounding results — if confirmed proper — reveal main issues with the rulebook physicists use to explain and perceive how the universe works on the subatomic degree.

“We think we might be swimming in a sea of background particles all the time that just haven’t been directly discovered,” Fermilab experiment co-chief scientist Chris Polly mentioned in a press convention. “There might be monsters we haven’t yet imagined that are emerging from the vacuum interacting with our muons and this gives us a window into seeing them.”

The rulebook, referred to as the Standard Model, was developed about 50 years in the past. Experiments carried out over many years affirmed over and once more that its descriptions of the particles and the forces that make up and govern the universe had been just about on the mark. Until now.

“New particles, new physics might be just beyond our research,” mentioned Wayne State University particle physicist Alexey Petrov. “It’s tantalizing.”

The United States Energy Department’s Fermilab introduced results Wednesday of 8.2 billion races alongside a observe outdoors Chicago that whereas ho-hum to most individuals have physicists astir: The muons’ magnetic fields don’t appear to be what the Standard Model says they need to be. This follows new results printed final month from the European Center for Nuclear Research’s Large Hadron Collider that discovered a shocking proportion of particles within the aftermath of high-speed collisions.

If confirmed, the U.S. results could be the most important discovering within the weird world of subatomic particles in almost 10 years, because the discovery of the Higgs boson, typically referred to as the “God particle,” mentioned Aida El-Khadra of the University of Illinois, who works on theoretical physics for the Fermilab experiment.

The level of the experiments, explains Johns Hopkins University theoretical physicist David Kaplan, is to drag aside particles and discover out if there’s “something funny going on” with each the particles and the seemingly empty space between them.

“The secrets don’t just live in matter. They live in something that seems to fill in all of space and time. These are quantum fields,” Kaplan mentioned. “We’re putting energy into the vacuum and seeing what comes out.”

Both units of results contain the unusual, fleeting particle referred to as the muon. The muon is the heavier cousin to the electron that orbits an atom’s heart. But the muon is just not half of the atom, it’s unstable and usually exists for under two microseconds. After it was found in cosmic rays in 1936 it so confounded scientists {that a} well-known physicist requested “Who ordered that?”

“Since the very beginning it was making physicists scratch their heads,” mentioned Graziano Venanzoni, an experimental physicist at an Italian nationwide lab, who’s one of the highest scientists on the U.S. Fermilab experiment, referred to as Muon g-2.

The experiment sends muons round a magnetized observe that retains the particles in existence lengthy sufficient for researchers to get a better take a look at them. Preliminary results recommend that the magnetic “spin” of the muons is 0.1% off what the Standard Model predicts. That might not sound like a lot, however to particle physicists it’s enormous — greater than sufficient to upend present understanding.

Researchers want one other year or two to complete analyzing the results of all of the laps across the 50-foot (14-meter) observe. If the results don’t change, it is going to depend as a serious discovery, Venanzoni mentioned.

Separately, on the world’s largest atom smasher at CERN, physicists have been crashing protons in opposition to one another there to see what occurs after. One of the particle colliders’ a number of separate experiments measures what occurs when particles referred to as magnificence or backside quarks collide.

The Standard Model predicts that these magnificence quark crashes ought to lead to equal numbers of electrons and muons. It’s type of like flipping a coin 1,000 occasions and getting about equal numbers of heads and tails, mentioned (*2*) chief Chris Parkes.

But that’s not what occurred.

Researchers pored over the information from a number of years and some thousand crashes and found a 15% distinction, with considerably extra electrons than muons, mentioned experiment researcher Sheldon Stone of Syracuse University.

Neither experiment is being referred to as an official discovery but as a result of there’s nonetheless a tiny probability that the results are statistical quirks. Running the experiments extra occasions — deliberate in each circumstances — may, in a year or two, attain the extremely stringent statistical necessities for physics to hail it as a discovery, researchers mentioned.

If the results do maintain, they’d upend “every other calculation made” on the planet of particle physics, Kaplan mentioned.

“This is not a fudge factor. This is something wrong,” Kaplan mentioned. That one thing could possibly be defined by a brand new particle or power.

Or these results could also be errors. In 2011, an odd discovering {that a} particle referred to as a neutrino appeared to be touring sooner than gentle threatened the mannequin, nevertheless it turned out to be the outcome of a free electrical connection downside within the experiment.

“We checked all our cable connections and we’ve done what we can to check our data,” Stone mentioned. “We’re kind of confident, but you never know.”


AP Writer Jamey Keaten in Geneva contributed to this report.


Follow Seth Borenstein on Twitter at @borenbears.


The Associated Press Health and Science Department receives assist from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely chargeable for all content material.

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