All Questions
12
questions
2
votes
0
answers
64
views
Masses of $SU(2)$ gauge bosons
I'm currently learning quantum field theory and I'm wondering one thing.The way I understood it is that in the $SU(2)$ Yang-Mills theory, all gauge bosons have the same mass due to the spontaneous ...
- 41
2
votes
0
answers
62
views
Predicting a nonzero mass for the photon
This is a concern I had after I had read the reply for a previous question I had: On the masslessness of the photon
So, I have been told that there are cases in which the gauge symmetry that preserves ...
- 3,982
2
votes
0
answers
128
views
What is the current theoretical and experimental understanding of the mass of the photon? [duplicate]
To what extend are we allowed to claim that the photon has some sort of mass, below some threshold. We certainly have no experimental evidence that the photon is completely massless, but, due to the ...
- 3,982
5
votes
0
answers
164
views
Intuition/Motivation behind necessity of Spontaneous Symmetry Breaking to generate massive gauge bosons
In field theory textbooks, it is shown that while any gauge invariant Lagrangian must involve massless gauge fields, to obtain massive gauge bosons, we must postulate the existence of a Higgs scalar ...
- 1,588
7
votes
1
answer
828
views
Vacuum expectation value (VEV) of a Gauge theory - Spontaneous Symmetry Breaking (SSB) - Higgs Mechanism
I am dealing with a sort of scalar QED with a term of SSB
\begin{equation}
\mathcal{L}=\left|D_{\mu} \phi\right|^{2}-\frac{1}{4}\left(F_{\mu \nu}\right)^{2}-V\left(\phi^{*} \phi\right)
\end{equation}
...
- 900
6
votes
0
answers
260
views
Is the vacuum degenerate in the Abelian Higgs model?
Consider the theory with Lagrangian
$$ \mathcal{L} = -\frac{1}{4}F_{\mu \nu} F^{\mu \nu} + (D_\mu \phi)^* (D^\mu \phi) - U(\phi) \,, $$
where $U(\phi)$ breaks the $U(1)$ symmetry of the system. If we ...
- 6,425
1
vote
0
answers
282
views
What exactly is the gauge invariance in relation to Higgs Field? [closed]
I have been studying about the "theoretical need for Higgs Boson" and the historical overview discusses about how theory of gauge invariance questioned the reliability of theories of electromagnetism ...
- 2,565
2
votes
1
answer
370
views
Gauge Theory of Superconductors
I'm trying to understand better the nature of the gauge redundancy and the Higgs mechanism in superconductors.
Specifically, I'm looking for a good reference that explains monopoles, vortices, and ...
46
votes
3
answers
9k
views
What role does "spontaneous symmetry breaking" play in the "Higgs Mechanism"?
In talking about Higgs mechanism, the first part is always some introduction to the concept of spontaneous symmetry breaking (SSB), some people saying that Higgs mechanism is the results of SSB of ...
- 6,095
0
votes
1
answer
92
views
Higgs mass and EW precision tests
I'm trying to understand how the Higgs mass can influence EW precision tests. In order to do that I'm using the following document (section 4.3):
http://arxiv.org/pdf/0706.0684v1.pdf
There are a ...
- 461
4
votes
1
answer
326
views
Local guage symmety implies causality
I read in a QFT book that local gauge symmetry implies causality. Could someone please explain that statement and why it's true?
Thank you.
- 3,447
6
votes
5
answers
1k
views
Problems with putting mass on Yang-Mills theory by hand
When Yang-Mills field theory was introduced, a problem is that the gauge invariance can not allow mass for the gauge field. Later people invented spontaneous symmetry breaking and Higgs mechanism to ...
- 6,391