The LHCb experiment cavern at CERN CERN/Brice, Maximilien A new particle has popped into existence at CERN’s Large Hadron Collider, a heavier proton-like particle that contains two charm quarks. Protons and neutrons are examples of a class of particles called baryons, which each contain three fundamental subatomic particles called quarks that come in a variety of so-called flavours. In the case of a proton, there are two “up” quarks and one “down” quark that make up the particle. But heavier quarks, like those known as charm quarks, can also combine to make baryons. However, because these unusual quark combinations are heavier and so more unstable, they often have fleetingly short lifetimes and quickly decay into other particles. In 2017, physicists working at CERN’s LHCb experiment glimpsed one of these exotic baryons, memorably named Xicc++, that was made up of two charm quarks and an up quark. This particle lived for only a trillionth of a second. Now, physicists working on the LHCb experiment have spotted the charm-filled sister particle to Xicc++, called the Xicc+particle, which contains a …