New particle discovered at LHC.

We can now officially add a new kind of baryon to the zoo of particles, one that was already predicted to exist but never before seen.Baryons are effectively triplets of smaller particles called quarks, which are elementary particles meaning they aren't made up of anything smaller payricles. Mist common ones are the protons and neutrons. This new baryon – made when two charm quarks and a single up bound together –  named Xi cc++.. It's four times heavier than a proton and could help challenge some ideas about how this kind of matter sticks together.

"Finding a doubly heavy-quark baryon is of great interest as it will provide a unique tool to further probe quantum chromodynamics, the theory that describes the strong interaction, one of the four fundamental forces," said Giovanni Passaleva , the spokesperson for the LHCb collaboration.

Being made of two heavy quarks should give Xi cc++ a slightly different structure to protons and neutrons.
"In contrast to other baryons, in which the three quarks perform an elaborate dance around each other, a doubly heavy baryon is expected to act like a planetary system, where the two heavy quarks play the role of heavy stars orbiting one around the other, with the lighter quark orbiting around this binary system," says former collaboration spokesperson Guy Wilkinson .

The LHCb experiment is a champion at spotting these kinds of decay products, as well as making heavy quarks.
The discovery has a high statistical significance at 7 sigma. Physicists break out the champagne at 5 sigma, so we can be pretty confident Xi cc++ was produced.

This research has been submitted to Physical Review Letters .