Editing Fundamental interaction (section)

=== Standard Model ===
{{Main|Standard Model}} {{See also|Standard Model (mathematical formulation)}}
[[Image:Standard Model of Elementary Particles.svg|thumb|350px|The [[Standard Model]] of elementary particles, with the [[fermion]]s in the first three columns, the [[gauge boson]]s in the fourth column, and the [[Higgs boson]] in the fifth column]]
The Standard Model of particle physics was developed throughout the latter half of the 20th century. In the Standard Model, the electromagnetic, strong, and weak interactions associate with [[elementary particles]], whose behaviours are modelled in [[quantum mechanics]] (QM). For predictive success with QM's [[Probability|probabilistic]] outcomes, [[particle physics]] conventionally models QM [[event (particle physics)|events]] across a field set to [[special theory of relativity|special relativity]], altogether relativistic quantum field theory (QFT).<ref>Meinard Kuhlmann, [http://www.scientificamerican.com/article.cfm?id=physicists-debate-whether-world-made-of-particles-fields-or-something-else "Physicists debate whether the world is made of particles or fields—or something else entirely"], ''Scientific American'', 24 Jul 2013.</ref> Force particles, called [[gauge boson]]s—''force carriers'' or ''[[messenger particles]]'' of underlying fields—interact with matter particles, called [[fermion]]s. 

[[Baryonic matter|Everyday matter]] is atoms, composed of three fermion types: [[quark|up-quarks and down-quarks]] constituting, as well as electrons orbiting, the atom's nucleus. Atoms interact, form [[molecule]]s, and manifest further properties through electromagnetic interactions among their electrons absorbing and emitting photons, the electromagnetic field's force carrier, which if unimpeded traverse potentially infinite distance. Electromagnetism's QFT is [[quantum electrodynamics]] (QED).

The force carriers of the weak interaction are the massive [[W and Z bosons]]. Electroweak theory (EWT) covers both electromagnetism and the weak interaction. At the high temperatures shortly after the [[Big Bang]], the weak interaction, the electromagnetic interaction, and the [[Higgs boson]] were originally mixed components of a different set of ancient pre-symmetry-breaking fields. As the early universe cooled, these fields [[symmetry breaking|split]] into the long-range electromagnetic interaction, the short-range weak interaction, and the Higgs boson. In the [[Higgs mechanism]], the Higgs field manifests Higgs bosons that interact with some quantum particles in a way that endows those particles with mass. The strong interaction, whose force carrier is the [[gluon]], traversing minuscule distance among quarks, is modeled in [[quantum chromodynamics]] (QCD). EWT, QCD, and the Higgs mechanism comprise [[particle physics]]' [[Standard Model]] (SM). Predictions are usually made using calculational approximation methods, although such [[perturbation theory (quantum mechanics)|perturbation theory]] is inadequate to model some experimental observations (for instance [[bound state]]s and [[soliton]]s). Still, physicists widely accept the Standard Model as science's most experimentally confirmed theory.

[[Beyond the Standard Model]], some theorists work to unite the electroweak and [[strong interaction|strong]] interactions within a [[Grand Unified Theory]]<ref>{{Cite journal|last=Krauss|first=Lawrence M.|title=A Brief History of the Grand Unified Theory of Physics|url=http://nautil.us/issue/46/balance/a-brief-history-of-the-grand-unified-theory-of-physics|journal=Nautilus|date=2017-03-16}}</ref> (GUT). Some attempts at GUTs hypothesize "shadow" particles, such that every known [[fermion|matter particle]] associates with an undiscovered [[Gauge boson|force particle]], and vice versa, altogether [[supersymmetry]] (SUSY). Other theorists seek to quantize the gravitational field by the modelling behaviour of its hypothetical force carrier, the [[graviton]] and achieve quantum gravity (QG). One approach to QG is [[loop quantum gravity]] (LQG). Still other theorists seek both QG and GUT within one framework, reducing all four fundamental interactions to a [[Theory of Everything]] (ToE). The most prevalent aim at a ToE is [[string theory]], although to model [[fermion|matter particles]], it added [[supersymmetry|SUSY]] to [[Gauge boson|force particles]]—and so, strictly speaking, became [[superstring theory]]. Multiple, seemingly disparate superstring theories were unified on a backbone, [[M-theory]]. Theories beyond the Standard Model remain highly speculative, lacking great experimental support.