New Discovery Suggests Quarks Can Undergo Explosive Fusion Reactions

Our Sun is powered by a fundamental phenomenon whereby atoms combine to unleash tremendous amounts of energy. But atoms might not be the only things that participate in this explosive reaction.

Image: Daniel Dominguez/CERN

Researchers at the Large Hadron Collider's LHCb experiment recently discovered a new particle whose constituent parts required a lot of energy to bind together. But another team found that a fusion reaction could exist between a pair of quarks to produce this particle, and others, releasing energy. They have some ideas for how to look for such a reaction - but no, you won't see quark bombs any time soon.

"The very short lifetimes of the heavy bottom and charm quarks preclude any practical applications of such reactions," the researchers write in the study published yesterday in Nature.

As you may remember from physics class, there are six kinds of quarks - the up and the down that make up pretty much everything you can see and then four other much rarer and much heavier ones. At the crux of this new research is a recently discovered arrangement of quarks called the Ξcc++ particle, also known as the "doubly charged, doubly charmed xi".

This doubly charged, doubly charmed xi has an up quark and two of the heavy charm quarks. It takes a comparatively large amount of energy to bind these charm quarks together, after which leftover energy is released. That released energy would be about on par with that from the nuclear reactions that produce our Sun's energy. It's a relatively small amount in the individual reactions - less than the amount of energy required to transmit a single bit of data - but a lot given that it's occurring in a subatomic particle.

Fusion reactions based on the heavier bottom quark - that is, if the resultant particle actually exists - could release 10 times more energy than this xi particle, write the authors. But it would be difficult to produce this kind of reaction. The bottom-containing particles we know about only stick around for a tiny fraction of a second, travelling somewhere between two and 22mm in CERN's LHCb experiment. Then, they lose energy and turn into other particles like a meteor breaking up in Earth's atmosphere.

It might be possible to study these quark fusion reactions by colliding heavy atoms, such as the beams of lead (stripped of their electrons) sometimes collided at the LHC, the authors write.

There are other exciting implications aside from whatever crazy sci-fi dream "quark fusion" might elicit. The high binding energy means maybe there are exotic atoms that contain charm or bottom quarks instead of up just and down quarks, writes Gerald A. Miller, a University of Washington-Seattle physicist, in Nature News & Views. Or maybe there's some explanation for the true identity of dark matter tied up somewhere in there.

Who knows. This is physics. Weird things happen all over the universe - including here on Earth.