Physicists baffled and excited by 2 experiments that challenge Rulebook

Preliminary results from two experiments suggest that something might be wrong with the basic way physicists think the universe works, a perspective that has the field of particle physics baffled and excited.

Smaller particles don’t quite do what is expected of them when they revolve around two different long-term experiments in the United States and Europe. The confusing results, if proven correct, reveal important problems with the rulebooks that physicists use to describe and understand how the universe works at the subatomic level.

Theoretical physicist Matthew McCullough of CERN, the European Organization for Nuclear Research, said that unraveling the mysteries could “take us beyond our current understanding of nature.”

The rulebook, called the Standard Model, was developed about 50 years ago. Experiments conducted for decades repeatedly stated that their descriptions of the particles and forces that form and govern the universe were virtually important. Bye now.

“New particles, new physics could be beyond our research,” said Alexey Petrov, a particle physicist at Wayne State University. “It’s tempting.”

U.S. Department of Energy Fermilab on Wednesday announced results of 8.2 billion races along a track outside of Chicago that, while they do for most people, physicists worry : the magnetic field around a fleeting subatomic particle is not what the standard model says it should be. This follows the new results published last month by CERN’s Large Hadron Collider which found a staggering proportion of particles after high-speed collisions.

Petrov, who did not participate in either experiment, was initially skeptical about the results of the Large Hadron Collider when suggestions first emerged in 2014. With the latest more complete results, he said he is now “Ecstatically cautious.”

The head of the experiments, explains Johns Hopkins University theoretical physicist David Kaplan, is to separate particles and find out if there is “something fun” with the particles and the seemingly empty space between them.

“Secrets don’t just live in matter. They live in something that seems to fill all the space and time. They are quantum fields, ”Kaplan said. “We’re putting energy in the vacuum and see what comes out.”

Both sets of results involve the strange and fleeting particle called the muon. The muon is the heaviest cousin of the electron orbiting the center of an atom. But the muon is not part of the atom, is unstable and usually only exists for two microseconds. After being discovered with cosmic rays in 1936, he confused scientists so that a famous physicist asked, “Who ordered it?”

“From the beginning, it made physicists scratch their heads,” said Graziano Venanzoni, an experimental physicist at an Italian national laboratory who is one of the leading scientists in the American Fermilab experiment, called Muon g-2. .

The experiment sends muons around a magnetized track that keeps the particles in existence long enough for researchers to see them up close. Preliminary results suggest that the magnetic “rotation” of the muons has a 0.1% discount over what the standard model predicts. This may not sound like much, but for particle physicists it is huge, more than enough to perfect current understanding.

Researchers need a year or two to finish analyzing the results of all laps around the 14-meter track. If the results do not change, it will be considered an important discovery, Venanzoni said.

Besides, at the world’s largest atomic destruction center, CERN, physicists have crashed protons against each other to see what happens next. One of several separate experiments on particle colliders measures what happens when particles called beauty or background quarks collide.

The standard model predicts that these beauty quark accidents should result in an equal number of electrons and muons. It’s like tossing a coin 1,000 times and getting an equal number of heads and tails, said Chris Parkes, head of the Great Hadron Collider’s beauty experiment.

But that’s not what happened.

The researchers analyzed data from several years and a few thousand accidents and found a 15 percent difference, with significantly more electrons than muons, said experiment researcher Sheldon Stone of Syracuse University.

Neither experiment is yet known as an official discovery because there is still a small probability that the results are statistical peculiarities. Running the experiments more often, predicted in both cases, could lead, in a year or two, to incredibly strict statistical requirements for physics to consider it a discovery, the researchers said.

If the results were maintained, they would increase “all other calculations performed” in the world of particle physics, Kaplan said.

“It’s not a fudge factor. That doesn’t happen, ”Kaplan said.

He explained that there may be some kind of particle or undiscovered force that can explain both strange results.

Or they may be mistakes. In 2011, a strange finding that it appeared that a particle called a neutrino appeared to travel faster than light threatened the model, but turned out to be the result of a weak electrical connection problem in the experiment.

“We checked all the cable connections and did our best to check our data,” Stone said. “We’re confident, but you never know.”

AP writer Jamey Keaten in Geneva contributed to this report.

Follow Seth Borenstein on Twitter at @borenbears.