Quantum Field Theory | ||
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... no spooky action at a distance (Einstein) | ||
Early Results
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Relativistic Quantum Mechanics | Klein-Gordon Equation Dirac Equation | |
The Dawn of QFT | Spinors Spin Feynman Slash Notation Antimatter Klein-Gordon Field Dirac Field Renormalisation Grassman Variable Conformal Field Theory | |
Countdown to the Standard Model
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From a framework to a model | Yang-Mills Theory Quantum Electrodynamics Quantum Chromodynamics Electroweak Theory Higgs Mechanism Standard Model |
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Semi-Classical Gravity and the Dark Age | Hawking Radiation Chandrashekhar Limit Inflation Problems with the Standard Model |
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Outlook
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Beyond the Standard Model | Beyond the Standard Model Quantum Gravity Theory of Everything |
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Related
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Related | De Donder-Weyl Theory | |
The Higgs Mechanism is a process whereby the spin-1 bosons of a gauge field can acquire mass without spoiling the theory's renormalisability.
In its simplest form (as in the Standard Model), a scalar field (the Higgs Field), charged under the Gauge Field that is to be "higgsed" (e.g. , in the Standard Model), acquires a nonzero Vacuum Expectation Value (a nonzero energy density for the field, even in its zero-particle ground state) thanks to a self-interaction potential. The Goldstone Bosons of this charged condensate add a third, spin-0 component to the two degrees of freedom of the massless spin-1 bosons, creating a massive spin-1 boson with three spin states, -1, 0, and +1.
Such a charged condensate is also capable of giving a mass to Chiral fermions in a Gauge-Invariant way, through an interaction term in which a left-handed fermion and a right-handed Fermion couple to the scalar field, e.g. as in the Yukawa Interaction terms in the Standard Model Lagrangian Density.
In Electroweak theory and Quantum Chromodynamics[]
The Electroweak Lagrangian Density is given by:
As you can see, a more natural description of the mass can be given by using a "Higgs Field" such that the following:
Lagrangian Density for the Higgs[]
The Higgs Field is a Scalar Field, also known as a Klein-Gordon Field, and it consequently satisfies the Klein-Gordon Equation. Like any other Klein-Gordon Field, it has the following/ Lagrangian Density:
. \
Electroweak Symmetry Breaking[]
The Higgs Mechanism makes W & Z Bosons massive, leaving photons massless by breaking Electroweak Symmetry, i.e. by breaking the symmetry.
The Higgs Boson[]
The Higgs Boson is an excitation of the Higgs Field.
It was experimentally detected at the LHC in 2011 at a mass of 125 Giga-electron-Volts. This experimental finding was again re-confirmed in 2012, and finally finalised in 2013, also thereby confirming a prediction of the Minimal Supersymmetric Standard Model. It is a popular myth that it confirms a prediction of the Non-Supersymmetric Standard Model.