The B meson is so named because it contains a bottom quark, one of six fundamental quark particles that account for most of the universe’s visible matter.
“If this is new physics,” Jure Zupan, a theoretical physicist at the University of Cincinnati, said of the current update, “it’s not significant enough.RELATED: These cheap noise-cancelling headphones come with a class-leading 50-hour battery life For that, the physicists will need to accumulate enough B meson decays to demonstrate a deviation of 1 in 1.7 million, akin to flipping 75 heads. For a fair coin, the odds of such a deviation are about 1 in 1,000.īut amid oodles of particle collisions, statistical fluctuations are bound to arise, so a 1-in-1,000 deviation doesn’t count as hard proof of a break with the standard model. Statistically, the deviation in the angular pattern is equivalent to flipping a coin 100 times and getting 66 heads, rather than the usual 50 or so. “Suddenly the consistency between the different angular observables got much better,” said Felix Kress, an LHCb researcher who helped crunch the numbers.
The collective significance of the anomalous angles grew slightly since the last analysis, and researchers say the new measurements also tell a more unified story. When experimentalists compared the various angles between the particles with the angles predicted by the standard model, they found a deviation from the expected pattern. Each transformation ends with four outbound particles hitting a ring-shaped detector. LHCb’s new analysis covered about 4,500 rare B meson decays, roughly doubling the data from their previous study in 2015. But because they are so rare, any tweaks coming from undiscovered particles or effects should be obvious. The standard model predicts the exceedingly low rate of these events and how they will play out. For every million B meson decays they see, one fringe event showcases a rebellious bottom quark metamorphosing into a “strange” quark instead, dropping a generation but keeping its negative charge. The LHCb collaboration scours the wreckage of particle pileups for exceptions to this rule. For instance, when the negatively charged heavy bottom quark in a B meson drops a generation, it usually becomes a middleweight, positively charged “charm” quark. Heavier quarks decay into their lighter variations, almost always switching their charge, too.
For unknown reasons, the quarks break down into three generations: heavy, medium, and light, each with quarks of opposite electric charge. “For the first time in certainly my working life, there are a confluence of different decays that are showing anomalies that match up,” said Mitesh Patel, a particle physicist at Imperial College London who is part of LHCb. But their collective drift suggests that the aberrations may be breadcrumbs leading beyond the standard model to a more complete theory. Taken alone, each oddity looks like a statistical fluctuation, and they may all evaporate with additional data, as has happened before. In their latest analysis, first presented at a seminar in March, the LHCb physicists found that several measurements involving the decay of B mesons conflict slightly with the predictions of the standard model of particle physics-the reigning set of equations describing the subatomic world. Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.
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