One of
the fundamental questions is that “what the matter is composed of?” In 1897,
atoms are known as the basic building blocks of matter. In the year 1911,
Ernest Rutherford demonstrated that when alpha particles are scattered on a
thin gold foil that the atom is composed of mostly empty space with a dense
core at its center which is called the nucleus. Thereafter, protons and
neutrons were discovered. In 1956, McAllister and Hofstadter published
experimental results of elastic scattering of the electrons from a hydrogen
target which revealed that the proton has an internal structure. In 1964,
Gell-Mann (and independently) Zweig proposed that nucleons are composed of
point-like particles which are called quarks. These quarks are postulated to
have spin-1/2, fractional electric charge. Combinations of different flavors of
quarks yield protons and neutrons which belong to the type of particles called
baryons (built up from three quarks) and mesons as (quark and an antiquark).
These two groups of particles are categorized as hadrons. The quarks showed
further decay properties which suggested that they have a substructure.
References
[1]
Gell-Mann, M. (1964) A Schematic Model of Baryons and Mesons. Physics Letters, 8, 214-215. https://doi.org/10.1016/S0031-9163(64)92001-3
[2]
Pati, J. and Salam, A. (1974) Lepton Number as the Fourth “Color”. Physical Review D, 10, 275-289. https://doi.org/10.1103/PhysRevD.10.275
[3]
Terazawa, H., Chikashige, Y. and Akama, K. (1977) Unified Model of the Nambu-Jona-Lasinio Type for All Elementary-Particle Forces. Physical Review D, 15, 480-487. https://doi.org/10.1103/PhysRevD.15.480
[4]
Harari, H. (1979) A Schematic Model of Quarks and Leptons. Physics Letters B, 86, 83-86. https://doi.org/10.1016/0370-2693(79)90626-9
[5]
Shupe, M. (1979) A Composite Model of Leptons and Quarks. Physics Letters B, 86, 87-92. https://doi.org/10.1016/0370-2693(79)90627-0
[6]
D’Souza, I.A. and Kalman, C.S. (1992) Preons: Models of Leptons, Quarks, and Gauge Bosons as Composite Objects. World Scientific Publishing, Hong Kong. https://doi.org/10.1142/9789814354769
[7]
Bilson-Thompson, S., Hackett, J., Kauffman, L. and Wan, Y.D. (2012) Emergent Braided Matter of Quantum Geometry. Symmetry, Integrability and Geometry: Methods and Applications, 8, 1-43.
[8]
Bevelacqua, J.J. (2012) Physical Interpretation of Electrodynamics within the Yang-Mills Theory. Physics Essays, 25, 369-373. https://doi.org/10.4006/0836-1398-25.3.369
[9]
Zenczykowski, P. (2016) The Harari–Shupe Observation without Preons—A Glimpse of Physics to Come? Acta Physica Polonica B, 47, 1011-1032. https://doi.org/10.5506/APhysPolB.47.1011
[10]
Larson, D.L. (2017) Additional Evidence and Predictions for the ABC Preon Model. Physics Essays, 30, 347-355. https://doi.org/10.4006/0836-1398-30.4.347
[11]
Raitio, R. (2017) Preon Model, Knot Algebra and Gravity. Open Access Library Journal, 4, e3432.
[12]
Bevelacqua, J.J. (2019) A First-Order Mass Formula for Quarks in Terms of Constituent Preons. Journal of Nuclear and Particle Physics, 9, 1-4.
[13]
Zel’dovich, Y.B. and Sakharov, A.D. (1966) The Quark Structure and Masses of Strongly Interacting Particles. Yadernaya Fizika, 4, 395-406.
[14]
Sakharov, A.D. (1980) Mass Formula for Mesons and Baryons. Journal of Experimental and Theoretical Physics, 51, 1059-1060.
[15]
Bevelacqua, J.J. (2018) Description of Selected Hexaquark States in Terms of a First-Order Mass Formula. Physics Essays, 31, 104-107. https://doi.org/10.4006/0836-1398-31.1.104
