Physicists are thrilled with the new W-boson dimension

Two workers on a collider of Fermilab particles.

The collaboration of hundreds of scientists has accurately measured the mass of the W-boson, the elementary particle responsible for weak nuclear power. The researchers, to their surprise, found that the boson is more massive than predicted Standard model particle physics, a working theory that describes several fundamental forces in the universe.

The new value was derived from 10-year experiments and calculations by 400 researchers from 54 different institutions around the world. All data were collected as a result of experiments on a four-story 4500-your Collider detector (abbreviated CDF-II) at the Fermilab Tevatron accelerator near Chicago, Illinois.

The CDF collaboration discovered W the mass of the boson is 80 433 +/- 9 MeV / c ^ 2, a figure which about twice as accurate as the previous measurement wt. To sense the scale, the new measurement puts the W-boson about 80 times the mass of the proton. The results of the team are as follows published today in science.

“The truth is that this is how most things in science often happen. We looked at the room, and we said, “Ha, that’s funny,” said David Tobacco, a physicist at A&M University of Texas and a CDF Collaboration spokesman, during a video call. “You could see how it just washes people away. It was quiet. We didn’t know what to do with it. “

“We were very pleasantly surprised [with the result]”- wrote Ashutosh Kotval, a physicist from Duke University and a member of the CDF collaboration, in an email. “We were so focused on the accuracy and reliability of our analysis that the value itself was like a wonderful shock.”

W-boson is associated with weak nuclear powerfundamental interaction responsible for one type of radioactive decay and nuclear fusion occurring in stars. Don’t worry – the mass of the boson is completely different than expected, doesn’t mean we’ve completely misunderstood things like fusion – but it does mean we still don’t understand much about the particles that make up our universe and how they interact.

A graph illustrating the exact result of a recent experiment.

“The standard model is the best we have for particle physics. This is surprisingly good. The problem is that we know we are wrong, ”Tobak said. “So, from a scientist’s point of view, experimenters are trying to say,‘ Yeah can we find something that the standard model doesn’t predict correctly that can give us a clue to what’s more true?“”

The standard model predicts the value of the mass of the W-boson, a value that the team tried to challenge by estimating 4 millions of W-candidate bosons created by collisions of protons and antiprotons in the Fermilaratory. Their result was higher than the standard model forecast on the colossal seven standard deviations. Kotval, who published five Increasingly accurate measurements of particle mass over the past 28 years have shown that “tthe probability that increasing the standard deviation by 7 will be a statistical coincidence, less than 1 in a billion ”.

Tobacco compared the measurement to measuring the weight of an 800-pound gorilla with an ounce of its true weight. As with many scientific experiments, especially in elementary particle physics, where masses are very small, the researchers closed their results to make sure that the calculations were not affected by any expectations or hopes of the research team.

But now, with an extremely accurate measurement that is so different from the previous ones, below It is estimated that physicists face the unenviable task of finding out what the Standard Model does not take into account. Of course, this is not the first time that subatomic physics has actually differed from humanity’s best assumptions. Last AprilThe Muon g-2 Collaboration has found further evidence of that property muon (another subatomic particle) may disagree with the predictions of the standard model. And two of the most important facts of our universe – gravity and dark matter – are famously not explained by the model.

The worker looks at the massive detector.

The Fermilab Collider Detector has a 4-story height and 4,500 tons.
Photo: © CORBIS / Corbis (Getty Images)

“To understand what a more fundamental theory might be, it is important to find phenomena that cannot be explained by [Standard Model]”- wrote by e-mail Claudio Companion, a physicist at the University of California, Santa Barbara, who is not involved in a recent study. “In other words, the phenomena where [Standard Model] the approximation is broken. ” Campagmar co-authored by Fr. An article about prospects about a new dimension.

To do this, there are experiments; they will explore the effects of today’s stay through various collision experiments. The results of ATLAS and Compact Muon Solenoid (CMS)two detectors on the CERN Large Hadron Collider (two detectors responsible for discovery of the Higgs boson 10 years ago). And then Great lighting Hadron Collider—An update what increase the number of possible collisions by 10 times– also increase chances see new compelling particles when it is completed in 2027.

The CDF collisions were between protons and antiprotons, whereas the Great Hadron Collider creates proton-proton collisions. Kotval said that if people ever built an electron-positron collider, this would allow accurate measurements and searches for rare Great processes Hadron Collider cannot produce.

As Martin Mulders, a physicist from CERN, wrote the Perspectives article in e-mail physicists will take a two-pronged approach to model verification: measure known particles (e.g., the W-boson) with increasing accuracy, and discover entirely new particles. New particles often found as a result of hunting: sifting through the noise of subatomic pits to see what was unexpectedly created.

The Tevatron accelerator stopped in 2011, immediately after the completion of the experimental launch of the collaboration. So today’s result is something like life after death for the legendary instrument, a huge W for the team and particle physics in general.

Read more: These X-rays are almost ready to push

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