Scientists at the Cern nuclear physics laboratory near Geneva have discovered a heavier version of the proton, the subatomic particle that sits at the heart of every known atom in the universe.
They spotted the particle in a shower of debris that lit up a detector at the Large Hadron Collider (LHC), located deep beneath the ground at Cern, which smashes protons together at close to the speed of light. The collisions recreate in microcosm conditions that prevailed just after the big bang, with the energy converting to particles that spray in all directions.
The newfound particle, which is four times heavier than the regular proton, should help physicists refine their understanding of the strong nuclear force that glues together the innards of all atomic nuclei. The force is unusual because it behaves like a rubber band, getting stronger as the distance between subatomic particles increases.
