In March, particle researchers presented intriguing evidence for new physics - maybe a new force of nature - at the Large Hadron Collider (LHC). Now, new data from CERN's massive particle collider appears to be bolstering the theory, albeit it has yet to be peer reviewed.
The LHCb collaboration, one of four primary teams at the LHC, analyzed 10 years of data on how unstable B mesons, generated momentarily in the massive machine, decayed into more familiar matter like electrons.
The standard model of particle physics, which underpins scientists' understanding of the subatomic world, firmly maintains that particles should break down into products including electrons at the same rate as they do into products including a heavier relative of the electron, a particle called a muon.
The standard model describes only three of the four fundamental forces - the electromagnetic force and strong and weak forces, leaving out gravity. It doesn't explain the dark matter that astronomers say dominates the Universe, and it can't explain how matter survived the Big Bang.
Most physicists therefore believe that there must be more cosmic elements still to be discovered, and investigating a class of fundamental particles known as beauty quarks is one of the most promising ways to learn more about what's out there.
However, CERN's findings from earlier this year imply that something strange is taking place. The B mesons do not decay in the way that the model predicts: instead of producing electrons and muons at the same rate, nature appears to choose the path that ends with electrons.
The result has a significance of 3.1 sigma in physics jargon, which means the possibility of it being a fluke is around one in 1,000. While it may appear to be compelling evidence, particle physicists often wait until a finding reaches a significance of five sigma, at which point the chances of it being a statistical fluke are lowered to one in a million or less.
The beauty quarks were coupled with "up" quarks in the March study. Their findings looked at two decays: one in which the beauty quarks were associated with "down" quarks and another in which they were linked with "up" quarks.
The fact that the pairing is different shouldn't matter - the decay that's going on deep down is the same, and scientists had expected to observe the same consequence if there is a new force out there.
What's new this time is that muon decays occurred only about 70% as frequently as electron decays, but with a bigger error, implying that the result is around two sigma from the standard model (around a two in a hundred chance of being a statistical anomaly).
This means that, while the result isn't precise enough to offer clear proof for a new force on its own, it does align extremely closely with the prior result, adding to the sense that CERN is on the verge of a huge breakthrough.
Scientists insist that they are very "cautious." There is still a long way to go before they can say with certainty that they are observing the influence of a fifth force of nature.
