Summary
A quark (kwɔːrk,_kwɑːrk) is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. All commonly observable matter is composed of up quarks, down quarks and electrons. Owing to a phenomenon known as color confinement, quarks are never found in isolation; they can be found only within hadrons, which include baryons (such as protons and neutrons) and mesons, or in quark–gluon plasmas. For this reason, much of what is known about quarks has been drawn from observations of hadrons. Quarks have various intrinsic properties, including electric charge, mass, color charge, and spin. They are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, also known as fundamental forces (electromagnetism, gravitation, strong interaction, and weak interaction), as well as the only known particles whose electric charges are not integer multiples of the elementary charge. There are six types, known as flavors, of quarks: up, down, charm, strange, top, and bottom. Up and down quarks have the lowest masses of all quarks. The heavier quarks rapidly change into up and down quarks through a process of particle decay: the transformation from a higher mass state to a lower mass state. Because of this, up and down quarks are generally stable and the most common in the universe, whereas strange, charm, bottom, and top quarks can only be produced in high energy collisions (such as those involving cosmic rays and in particle accelerators). For every quark flavor there is a corresponding type of antiparticle, known as an antiquark, that differs from the quark only in that some of its properties (such as the electric charge) have equal magnitude but opposite sign. The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964.
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Related courses (19)
PHYS-416: Particle physics II
Presentation of the electroweak and strong interaction theories that constitute the Standard Model of particle physics. The course also discusses the new theories proposed to solve the problems of the
PHYS-415: Particle physics I
Presentation of particle properties, their symmetries and interactions. Introduction to quantum electrodynamics and to the Feynman rules.
PHYS-311: Nuclear and particle physics I
Introduction générale sur l'état des connaissances en physique des particules élémentaires: de la cinématique relativiste à l'interprétation phénoménologique des collisions à haute énergie.
Show more
Related MOOCs (8)
Global Arctic
The Global Arctic MOOC introduces you the dynamics between global changes and changes in the Arctic. This course aims to highlight the effects of climate change in the Polar region. In turn, it will u
Smart Cities, Management of Smart Urban Infrastructures
Learn about the principles of management of urban infrastructures in the era of Smart Cities. The introduction of Smart urban technologies into legacy infrastructures has already resulted and will con
Smart Cities, Management of Smart Urban Infrastructures
Learn about the principles of management of urban infrastructures in the era of Smart Cities. The introduction of Smart urban technologies into legacy infrastructures has already resulted and will con
Show more