Nuclear fusion occurs when two or more atoms combine, unleashing a large amount of energy. At least, that’s what we thought.

A new paper suggests that it’s not just atoms that undergo fusion. Writing in the journal Nature, researchers at the Large Hadron Collider’s LHCb experiment in CERN say they have evidence for fusion taking place between subatomic particles known as quarks.

“In nuclear fusion, energy is produced by the rearrangement of protons and neutrons,” an accompanying New and Views article notes. “The discovery of an analogue of this process involving particles called quarks has implications for both nuclear and particle physics.”

The discovery was made when particles were smashed together in CERN’s underground ring, which is 27 kilometers (17 miles) long, at almost the speed of light. When studying the data from those collisions, scientists look for odd particles and other unusual things.

Quarks come in six flavors: up, down, top, bottom, charm, and strange. In June this year, scientists noticed the appearance of a baryon (a subatomic particle made of three quarks, such as protons and neutrons) made of two charm quarks and an up quark. They found that when the charm quarks fused, they produced a binding energy of 130 MeV (megaelectronvolts) and released 12 MeV.

However, more impressively they also spotted the fusion of two bottom quarks, which are more energetic than charm quarks. These binded with an energy of 280 MeV, releasing 138 MeV.

To put those figures in context, the individual nuclear fusion event between deuterons and tritons that takes place in a hydrogen bomb release just 18 MeV.

Fortunately, however, you don’t need to worry about any military applications of this latest discovery. Speaking to Live Science, lead author Marek Karliner of Tel Aviv University in Israel said the researchers checked to make sure there were no practical applications of this energy release.

Thankfully, there isn’t. Nuclear bombs require not just one of these events, but billions taking place in a chain reaction. Quarks disappear in a pico second (one-trillionth of a second), making such a quark bomb impossible.

"If I thought for a microsecond that this had any military applications, I would not have published it," said Karliner.

For that same reason, studying this process will be difficult too. But the scientists hope that in a couple of years, experiments at CERN could reveal more about quark fusion.

(H/T: Live Science)