Later, he found the word "quark" in James Joyce's book Finnegans Wake, and used the spelling but not the pronunciation:Īnd sure any he has it's all beside the mark. The word was originally coined by Murray Gell-Mann as a nonsense word rhyming with "pork", but without a spelling. This is a direct consequence of confinement. Isolated quarks are never found naturally they are almost always found in groups of two ( mesons) or groups of three ( baryons) called hadrons. Quarks are the only fundamental particles that interact through all four of the fundamental forces.Īntiparticles of quarks are called antiquarks. It is this which makes the difference when quarks clump together to form protons or neutrons: a proton is made up of two up quarks and one down quark, yielding a net charge of +1 while a neutron contains one up quark and two down quarks, yielding a net charge of 0.
(Their names were chosen arbitrarily based on the need to name them something that could be easily remembered and used.) The up and down varieties survive in profusion, and are distinguished by (among other things) their electric charge. There are six different types of quark, usually known as flavors: up, down, charm, strange, top, and bottom. Various species of quarks combine in specific ways to form protons and neutrons, in each case taking exactly three quarks to make the composite particle in question. A quark ( IPA: /kwɔrk/) is a generic type of physical particle that forms one of the two basic constituents of matter, the other being the lepton.