If you’re up for an outing, but don’t want to leave the couch, how about a trip to the quark zoo? Scientists at CERN, working on an experiment called LHCb, have found substantial evidence for a particle made of 4-quarks. The protons and neutrons that make up atoms are made of 3 quarks, and plenty of other 3-quark particles have been found; 2-quark pairs are also quite common. But if 4-quark states exist, it could indicate a whole zoo of increasingly larger quark particles. This isn’t the first time such a thing has been spotted, but scientists are still investigating the weight of those findings. Tomasz Skwarnicki, one of the scientists who worked on the new result from LHCb, says this is one of the strongest pieces of evidence yet for the existence of a 4-quark state.
Oh, and if you do visit the particle zoo, be sure to check out the glueballs.