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Essentials of Data Analytics
Published in Adedeji B. Badiru, Data Analytics, 2020
Relativistic quantum field theory had its first great success with quantum electrodynamics, which explains the interaction of charged particles with the quantized electromagnetic field. Exploration of non-Abelian gauge theories led next to the spectacular unification of the electromagnetic and weak interactions. Then, with insights developed from the quark model, quantum chromodynamics was developed to explain the strong interactions. This theory predicts that quarks are bound more tightly together as their separation increases, which explains why individual quarks are not seen directly in experiments. The standard model, which incorporates strong, weak, and electromagnetic interactions in a single quantum field theory, describes the interaction of quarks, gluons, and leptons, and has achieved remarkable success in predicting experimental results in elementary particle physics.
Introduction and History
Published in Volker Ziemann, ®, 2019
And this forces us to briefly discuss the fundamental forces that govern all interactions. First known was the gravitational force, put on a sound theoretical foundation, first by Newton in 1687, and later by Einstein with the general theory of relativity in 1915. The second type of fundamental forces known were electric and magnetic forces. In 1865, Maxwell published a theory that explains these forces in a unified way as a single underlying force, the electro-magnetic interaction. Later these forces were associated with the exchange of particles, the photons. The fundamental force responsible for radioactive decay is called the weak interaction and we now know that it is mediated by Z and W–bosons. The last fundamental force is called the strong interaction and is responsible for the forces inside the nucleus and between quarks. Since the 1970s we know that the strong interaction is mediated by carriers called gluons. Here we already see another ordering scheme. There are particles that constitute matter and there are force-carriers, the interaction bosons such as photons, Zs, or gluons. The theory that was developed during the 1960s and 1970s that places the electro-magnetic, weak and strong interaction in a coherent framework is called the standard model. This model was extremely successful in explaining and predicting sub-atomic phenomena, culminating in the discovery of the Higgs-boson in 2012.
The evolution of future societies with unlimited energy supply?
Published in Kléber Ghimire, Future Courses of Human Societies, 2018
However, for modern physics, forces are not transmitted directly between interacting objects, but instead are described by intermediary entities called fields. All four of the known fundamental forces are mediated by fields. The four fundamental interactions are: Strong interaction: the interaction responsible for holding neutrons and protons together to form atomic nuclei. The exchange particle that mediates this force is the gluon.Electromagnetic interaction: the familiar interaction that acts on electrically charged particles. The exchange particle that mediates this force is the photon.Weak interaction: a short-range interaction responsible for radioactivity, that acts on electrons, neutrinos, and quarks. The exchange particles that mediate this force are the W and Z bosons.Gravitational interaction: a long-range attractive interaction that acts on all particles. The postulated exchange particles are the graviton.
On the unsolvability of bosonic quantum fields
Published in Philosophical Magazine, 2018
The understanding within quantum chromodynamics (QCD), the QFT of strong interactions, of the observed striking properties of this fundamental force – such as colour confinement, mass gap generation, spontaneous chiral symmetry breaking, string effects and so on – turned out to be an extraordinarily difficult task. Standard perturbative expansion in the interaction coupling was not working and it seemed it was necessary to exactly solve the theory to succeed – or at least that it was necessary to find a different kind of expansion.