A quark is a type of elementary particle and a fundamental constituent of matter. 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 top quark, first observed at Fermilab in 1995, was the last to be discovered.
About Quark in brief
A quark is a type of elementary particle and a fundamental constituent of matter. 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 top quark, first observed at Fermilab in 1995, was the last to be discovered. Quarks are spin-1⁄2 particles, implying that they are fermions according to the spin–statistics theorem. They are subject to the Pauli exclusion principle, which states that no two identical fermion can simultaneously occupy the same quantum state. Unlike leptons, quarks possess color charge, which causes them to engage in the strong interaction. The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964. There was little evidence for their physical existence until deep inelastic scattering experiments at the Stanford Linear Accelerator Center in 1968. A great number of hadrons are known, most of them differentiated by their quark content and the properties these constituent quarks confer. The existence of ‘exotic’ hadrons with more valence quarks, such as tetraquarks and pentaquarks, was conjectured from the beginnings of the quarks model in the early 21st century but not discovered until the mid-20th century. The first generation of quarks are grouped into three generations, each comprising up and down, the second and third quarks and the fourth generation.
Only Heavier quarks can be created in high-energy collisions, and there is strong indirect evidence that no more than three generations exist. Particles in higher generations generally have greater mass and less stability, causing them to decay into lower-generation particles. The Standard Model is the theoretical framework describing all the currently known elementary particles. This model contains six flavors of quark, named up, down, strange, charm, bottom, and top. The most common baryons are the proton and the neutron, the building blocks of the atomic nucleus. The most stable of which are protons and neutrons, the components of atomic nuclei. The resulting attraction between different quarks causes the formation of composite particles known as hadrons. The quarks that determine the quantum numbers ofHadrons are called valences quarks; apart from these, any hadron may contain an indefinite number of virtual “sea’ quarks’, antiquarks, and gluons, which do not influence its quantum numbers. For every quark flavor there is a corresponding type of antiparticle that differs from the quark only in that some of its properties have equal magnitude but opposite sign. This is in contrast to bosons, of which any number can be in the same state. The heavier quarks rapidly change into up andDown quarks through a process of particle decay: the transformation from a higher mass state to a lower mass state.