Quark Glog

Murray Gell-Mann and George Zweig

Murray Gell-Mann

George Zweig

Done by Lauren Inman, Yisang Yang and Kristie Jones

What is a quark? Quarks are fundamental matter particles that make up protons, neutrons and other hadrons. (Hadrons are particles made from quarks). There are six different types of quarks. Each quark type is classified as a different flavor. Quarks only exist in hadrons because they are confined by strong force fields. The mass of several quarks cannot be measured by isolating them. The mass of a hadron gets contributions from quark kinetic energy and from potential energy due to strong interactions. For hadrons made of light quark types, the quark mass is a small contribution to the total hadron mass. The six flavors of quarks are up, down, charm, strange, top and bottom. Each flavor has three varieties of “colors”: red, green, and blue. All eighteen types have different electric charges. Three quarks form a proton or a neutron.

Do YOU know what a quark is?

Murray Gell-Mann: In 1969 Murray Gell-Mann received the Nobel Prize in Physics for his work on the theory of elementary particles. He has written a book titled “The Quark and the Jaguar,” published in 1944, in which contains his ideas on simplicity and complexity. One of Gell-Mann’s contributions to Physics was called the eightfold way.” This scheme established order from the chaos created by the discovery of some 100 kinds of particles in collisions involving atomic nuclei. He found that all of those particles, including the proton and neutron, are made up of building blocks which he named “quarks,” with very unusual properties. This idea has since been fully confirmed by experiment. Quarks are permanently confined by forces coming from the exchange of “gluons.” Later Gell-Mann and others constructed the quantum field theory of quarks and gluons, called “quantum chromodynamics,” which seems to account for all the nuclear particles and their strong interactions.

Did you know? The quark’s name originated as a playful word, sounding something like “kwork.” Murray Gell-Mann later came across the line “Three quarks for Master Marks” in James Joyce’s “Finnegan’s Wake,” and the particle became known as a quark.

George Zweig: George Zweig proposed the existence of quarks while attending the California Institute of Technology in 1964. His theory was independent of Murray Gell-Mann. Zweig referred to the later quarks as “aces,” after the four playing cards, because he believed there were four of them. Like Gell-Mann, he realized that the properties of particles could be explained by treating them as triplets of other particles (which are referred to as quarks and aces). However, unlike Gell-Mann, he accepted these as physically real particles.