As opposed to simply energy, the universe is also made of stuff. Not a whole lot of stuff, mind you, at least if you compare the matter we experience to the vast emptiness of space or the preponderance of dark matter. But enough.
The continued prevalence of matter has long been one of my favorite attributes of the universe, given that it allows for the existence of galaxies, and Guinness. However, it’s the source of confusion to physicists. In short, there should have been equal amounts of matter and antimatter present at the creation of the universe, which doesn’t make sense:
If matter and antimatter had come out even in those first moments, they would have instantly destroyed each other, leaving nothing but energy behind [TIME].
But they didn’t; as sure as I’m sitting here, matter won out. And this week, at the Tevatron particle smasher in Illinois, a new clue to the problem has emerged. In a study for Physical Review D, physicist Dmitri Denisov and his colleagues explain that in long-running proton-antiproton collisions (nearly 8 years of them), they saw a slight favoritism toward normal matter in a particular place:
“While colliding protons and antiprotons, which creates neutral B mesons, we would expect that when they decay we will see equal amounts of matter and antimatter,” Denisov says. “For whatever reason, there are more negative muons, which are matter, than positive muons, which are antimatter.” According to DZero member Gustaaf Brooijmans, a physicist at Columbia University, “We observe an asymmetry that is close to 1 percent.” [Scientific American].
The Tevatron team doesn’t know why this asymmetry is there; they just know that it doesn’t make sense based on the current understanding of the universe. And scientists love it when there’s a puzzle to solve. Says team member and particle physicist Stefan Soldner-Rembold:
‘Many of us felt goosebumps when we saw the result,” Soldner-Rembold said. “We knew we were seeing something beyond what we have seen before — and beyond what current theories can explain” [Chicago Sun-Times].
The physics can’t rule out that a new particle would explain this weirdness. And there’s an obvious place to look for it: Europe’s shiny new Large Hadron Collider.
If it turns out that a new particle is in fact responsible for the odd tendency of B mesons to favor matter over antimatter, it might be unmasked in the unprecedented high-energy collisions at the Large Hadron Collider, or LHC. But don’t count out the workhorse stateside, which has a head start of many years—and reams of well-understood data—on its more powerful European counterpart [Scientific American].
DISCOVER: The 11 Great Unanswered Questions of Physics
Cosmic Variance: Matter v. Antimatter 1: The Baryon Asymmetry
80beats: Ghost in the Machine? Physicists May Have Detected a New Particle at Fermilab
80beats: Rumors of the LHC’s Demise Have Been Greatly Exaggerated
80beats: Physicists Shoot Neutrinos Across Japan to an Experiment in an Abandoned Mine