Podcast: A Trip to the Quark Zoo

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 t...