All Questions
8
questions
5
votes
2
answers
249
views
Theory of weak interactions
Why don't we have a theory solely of weak interaction, like QED or QCD? I.e $SU(2)$ gauge theory describing neutrinos and massive $W^{+-}$ bosons.
But instead we have a unified electroweak theory ...
- 377
1
vote
0
answers
51
views
Goldstone and longitudinal polarization equivalence between off-shell $W$s
If I understand correctly, the couplings of the longitudinal component of the $W$ and $Z$ bosons should be "equivalent" to the Goldstone bosons they ate after SSB.
In practice, this makes ...
- 41
1
vote
1
answer
99
views
Why is the relation $M_W=M_Z\cos\theta_W$ true only at tree-level?
In Glashow-Weinberg-Salam electroweak theory, the relation $$M_W=M_Z\cos\theta_W\tag{1}$$ is said to be remain true only at the tree-level; it receives corrections from the loop diagrams. See here. ...
- 26.7k
1
vote
0
answers
62
views
Could electroweak interactions derive from higgsing of gauged chiral symmetry?
A recent question discussed the practice of introducing electroweak interactions into chiral perturbation theory by gauging part of the chiral symmetry. Gauging chiral symmetry is normally regarded as ...
- 13.3k
1
vote
2
answers
1k
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What happens to the Weak Interaction after Electroweak Symmetry Breaking?
As far as I know the electroweak theory only holds for some energy scale (probably the one we use at the LHC). For that scale there is a gauge theory for the electroweak interaction. Under this scale ...
- 839
7
votes
1
answer
1k
views
Georgi-Glashow model and the VEV of the scalar field
Consider the Georgi-Glashow model, an $SU(2)$ gauge theory with a real scalar in the adjoint (thus a 3-vector in the colour space) $\phi$. The Lagrangian is
$$ L = -\frac{1}{4g^2} F_{\mu \nu}^{\, a} ...
- 2,188
1
vote
1
answer
155
views
Transformations of electroweak gauge field $W_\mu$ under $U(1)_{e.m.}$
As the vector boson field $W_\mu$ is, together with $Z^0$, the gauge field for the Standard electroweak model, I know it transforms as a connection under the $SU(2)\times U(1)_Y$ group. But, when this ...
37
votes
2
answers
7k
views
What is (meant by) a non-compact $U(1)$ Lie group?
In John Preskill's review of monopoles he states on p. 471
Nowadays, we have another way of understanding why electric charge is quantized. Charge is quantized if the electromagnetic $U(l)_{\rm em}$...
- 16.9k