The new award was extracted from 10 years of experiments and calculations by 400 researchers at 54 different institutions around the world, a breathtaking endeavor. All data were collected from experiments on a four-story, 4,500-tonne Collider Detector (CDF-II for short) at Fermilab’s Tevatron accelerator near Chicago, Illinois. The CDF Collaboration found that the mass of boson W is 80,433 +/- 9 MeV / c ^ 2, a number that is approximately twice as accurate as its previous mass measurement. For a sense of scale, the new measurement places the W boson at about 80 times the mass of a proton. The team’s results are published today in Science. “The truth is that what happened here is how often most things happen in science. “We took a look at the number and said, ‘Ha, that’s funny,’” said David Toback, a physicist at Texas A&M University and a spokesman for the CDF Collaboration, in a video call. “You could see it washing people. It was quiet. We did not know what to do with it. “ “It simply came to our notice then [with the result]Wrote Ashutosh Kotwal, a physicist at Duke University and a member of the CDF collaboration, in an email. “We were so focused on the accuracy and robustness of our analysis that the value itself was like a wonderful shock.” G / O Media may receive a commission The W boson is associated with weak nuclear power, a fundamental interaction responsible for a type of radioactive decay, and nuclear fusion that occurs in stars. Do not worry – the boson having a very different mass than expected does not mean that we have completely misunderstood things like nuclear fusion – but it does mean that there is still much we do not understand about the particles that make up our universe and how they interact. “The Standard Model is the best we have for particle physics. It’s amazingly good. “The problem is that we know we’re wrong,” Toback said. “Well, from the scientist’s point of view, the experimenters are trying to say, ‘Yeah, can we find something that the Standard Model does not predict correctly, that could give us an idea of what is truer?’ The Standard Model predicts a value for the mass of the W boson, a value that the team sought to challenge by evaluating 4 million candidate W bosons created by collisions between protons and antiprotons at Fermilab. Their result was higher than the prediction of the Standard Model with imposing seven standard deviations. Kotwal, who has published five increasingly accurate measurements of particle mass over the past 28 years, said that “the probability of increasing the standard deviation by 7 as a statistical error is less than 1 in a billion.” Toback likened the measurement to a 800-pound gorilla weighing an ounce of its actual weight. As with many scientific experiments – especially in particle physics, where the masses are so small – the researchers blinded their results to ensure that the calculations were not affected by any expectations or hopes of the research team. But now, with an extremely accurate measurement so different from previous, lower estimates, physicists have an incredible task of understanding what the Standard Model does not take into account. This is certainly not the first time that subatomic physics has proven to be truly different from humanity’s best conjectures. Last April, the Muon g-2 partnership found further evidence that the properties of the muon (another subatomic particle) may not be in line with the predictions of the Standard Model. And two of the most important events in our universe – gravity and dark matter – are not famously explained by the model. The Fermilab Collider Detector has a height of 4 floors and 4,500 tons. Photo: © CORBIS / Corbis (Getty Images) “In order to understand what could be the most fundamental theory, it is important to find phenomena that cannot be explained by [Standard Model]Sent an email to Claudio Campagnari, a physicist at the University of California, Santa Barbara, not related to the recent study. “In other words, phenomena where the [Standard Model] the approach collapses “. Campagmari wrote an article in Perspectives about the new measurement. There are experiments that do just that. will explore the implications of today’s finding with different collision experiments. There are still results from ATLAS and the Compact Muon Solenoid (CMS), two detectors in CERN’s Large Hadron Collider (the two detectors responsible for the discovery of the Higgs boson 10 years ago). And the Large High-Brightness Hadron Collider — an upgrade that will increase the number of possible collisions by 10 — will also increase the chances of seeing exciting new particles when 2027 is completed. CDF collisions were between protons and antiprotons, while the Large Hadron Collider produces proton-proton collisions. Kotwal said that if humans ever built an electron-positron accelerator, it would allow accurate measurements and searches for rare processes that the Large Hadron Collider could not produce. As CijN physicist Martijn Mulders wrote in an email to the Perspectives article, physicists will take a two-pronged approach to testing the model: measuring known particles (such as the W boson) with increasing accuracy, as well as discovering completely new particles. . New particles are often spotted through the “hit” hunt: sifting through the noise of mosh subatomic pits to see what was created unexpectedly. The Tevatron accelerator closed in 2011, shortly after the completion of the pilot operation of the partnership. So today’s result is something like a life after death for the famous instrument, a huge W for the team and particle physics as a whole. More: These processed X-rays are almost ready to stick things
