Electromagnetic gauge

The second Higgs field acts in such a way that if the vacuum expectation value is zero, ( ) = 0, then the symmetry breaking mechanism effectively collapses to the Higgs mechanism of the standard SU(2) x U(l) electroweak theory. The result is a vector electromagnetic gauge theory 0(3)/> and a broken chiral SU(2) weak interaction theory. The mass of the vector boson sector is in the A(3) boson plus the W and Z° particles. 

In the second example BCS theory relates the appearance of a superconducting state to the breakdown of electromagnetic gauge symmetry by interaction with regular ionic lattice phonons and the creation of bosonic excitations. This theory cannot be extended to deal with high Tc ceramic superconductors and it correlates poorly with normal-state properties, such as the Hall effect, of known superconductors. It is therefore natural to look for alternative models that apply to all forms of superconductivity. 

If such a function now describes the behaviour of a particle through some differential equation, it is important to know that the phase factor will also be modified by differential operators such as V and d/dt. The transformed function therefore cannot satisfy the same differential equation as ip, unless there is some compensating field in which the particle moves, that restores the phase invariance. The necessary appearance of this field shows that local phase invariance cannot be a property of a free particle. It is rather obvious to make the connection with electromagnetic gauge invariance since equation (17) with a = qA is precisely the transformation associated with electromagnetic gauge invariance. 

The photon was chosen so that the theory remained invariant under transformations generated by (7 + T3) which for < ,0 would be the usual electromagnetic gauge transformations. To check what happens to the photon under this transformation we must set 0 x) = 0 (x) = 0 and 6 x) = 6 x) in (4.2.3). 

This unwelcome discovery is potentially catastrophic for our unified weak and electromagnetic gauge theory. There we have lots of gauge invariance, many conserved currents, both vector and axial-vector, and hence many Ward identities. Moreover the Ward identities play a vital role in proving that the theory is renormalizable. It is the subtle interrelation of matrix elements that allows certain infinities to cancel out and render the theory finite. Thus we cannot tolerate a breakdown of the Ward identities, and we have to ensure that in our theory these triangle anomalies do not appear. 

Now the Lagrangean associated with the nuclear motion is not invariant under a local gauge transformation. Eor this to be the case, the Lagrangean needs to include also an interaction field. This field can be represented either as a vector field (actually a four-vector, familiar from electromagnetism), or as a tensorial, YM type field. Whatever the form of the field, there are always two parts to it. First, the field induced by the nuclear motion itself and second, an externally induced field, actually produced by some other particles E, R, which are not part of the original formalism. (At our convenience, we could include these and then these would be part of the extended coordinates r, R. The procedure would then result in the appearance of a potential interaction, but not having the field. ) At a first glance, the field (whether induced internally... 

The principal weighing technologies in use currently are mechanical, hydraulic, strain-gauge, electromagnetic force compensation, and nuclear. 

In the Hamiltonian conventionally used for derivations of molecular magnetic properties, the applied fields are represented by electromagnetic vector and scalar potentials [1,20] and if desired, canonical transformations are invoked to change the magnetic gauge origin and/or to introduce electric and magnetic fields explicitly into the Hamiltonian, see e.g. refs. [1,20,21]. Here we take as our point of departure the multipolar Hamiltonian derived in ref. [22] without recourse to vector and scalar potentials. 

Hence, the method of Mead and Truhlar [6] yields a single-valued nuclear wave function by adding a vector potential A to the kinetic energy operator. Different values of odd (or even) I yield physically equivalent results, since they yield (< )) that are identical to within an integer number of factors of exp(/< )). By analogy with electromagnetic vector potentials, one can say that different odd (or even) I are related by a gauge transformation [6, 7]. 

The electromagnetic field is a well-known example of a gauge theory. A gauge transformation of the form... 

The concept of a gauge field and the notion of gauge invariance originated with a premature suggestion by Weyl [42] how to accommodate electromagnetic variables, in addition to the gravitational field, as geometric features of a differential manifold. 

The identical transformation, equation (6), of the electromagnetic vector potentials was found before to leave the fields unaffected or gauge invariant. The fields Atl are not gauge invariant, but the fields described by the tensor, equation (33)... 

The electromagnetic field may now formally be interpreted as the gauge field which must be introduced to ensure invariance under local U( 1) gauge transformation. In the most general case the field variables are introduced in terms of the Lagrangian density of the field, which itself is gauge invariant. In the case of the electromagnetic field, as before,... 

Gauging the Wess-Zumino term with to respect the electromagnetic interactions yields the familiar 7r° — 27 anomalous decay. This term [35] can be written compactly using the language of differential forms. It is useful to introduce the algebra-valued Maurer-Cartan one form a = a dx = (d U) U l dxF = (dU) U l which transforms only under the left SUp 3) flavor group. The Wess-Zumino effective action is... 

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