All Questions
37
questions
3
votes
1
answer
96
views
Are Higgs mechanism and SSB different phenomena?
In the Standard Model, the Higgs mechanism is associated with the Spontaneous Symmetry Breaking (SSB).
My understanding is that it is the Higgs field which breaks the $SU(2) \times U(1)$ symmetry at a ...
- 1,669
2
votes
0
answers
68
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 ...
- 43
1
vote
0
answers
39
views
Loop Calculations of A Spontaneous Broken gauge theory with fermions
Let me first rephrase the background. Consider adding a massless fermion to the spontaneously broken $U(1)$ gauge theory through a chiral interaction:
$$
\mathcal{L}=\bar{\psi}_{L}i \gamma_{\mu}D^{\mu}...
- 81
0
votes
1
answer
59
views
Can we prove in general that gauge fields associated with broken generators form representations of the unbroken group?
The title is a bit ambiguous. More specifically, I'm asking:
Are all coupling between massive gauge fields (associated with broken generators) and massless gauge fields of the unbroken group are in ...
- 619
2
votes
1
answer
143
views
Spontaneous Symmetry Breaking, Vacuum Degeneracy, and Goldstone Bosons applied to large gauge transformations
I am reading Strominger's lecture notes on the infrared structure of gravity and gauge theory. I am trying to understand subchapter 2.11, where the author focuses on the notions of "Spontaneous ...
- 3,992
0
votes
1
answer
113
views
Lattice $SU(2)$ Higgs model in unitary gauge
I'm currently reading the book Quantum Fields on a Lattice by I. Montvay and G.Münster, and in section 6.1 they describe lattice actions for various higgs models. And I got confused at the moment ...
- 343
1
vote
2
answers
165
views
Comparing "gauge theory" and "(global) spontaneous symmetry breaking"
To construct an effective field theory with spontaneously broken global symmetries, we need building blocks for the Lagrangian (such as covariant derivatives) that seem similar to gauge theory ...
- 213
3
votes
1
answer
260
views
Structure Group vs Gauge Group in Gauge Spontaneous Symmetry Breaking
Recently I’ve been learning about spontaneous symmetry breaking (SSB) for gauge theories. I’ve stumbled across some really helpful resources, such as Hamilton’s Mathematical Gauge Theory – With ...
- 559
2
votes
1
answer
599
views
Nonlinear symmetry realization: what is it for and caveats?
I have several doubts regarding the nonlinear realization of a spontaneously broken symmetry and hope they are appropriate to be grouped, and I appreciate any insights.
Consider the group breaking ...
- 1,742
0
votes
0
answers
168
views
$SU(3)$ and $SU(3)\times SU(2)\times U(1)$ Symmetry Breaking [duplicate]
For my master's project I was doing spontaneous symmetry breaking in which I covered U(1), SU(2), SU(2)×U(1) symmetry breaking. My supervisor has said that for the project this much is enough. But now ...
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
3
votes
1
answer
203
views
Gauge invariance at the quantum level post SSB in the case of Abelian Gauge theory
On page 690 in Peskin & Schroeder's book, the Higgs mechanism is discussed in the context of an Abelian Gauge theory. After the SSB, among the many terms that appear, there is a mass term for the ...
- 823
2
votes
0
answers
75
views
Current state of the Gribov-Zwanziger formalism and the softly broken BRST symmetry
I hope to get a little bit more clarification about the topics. My confusion arises from the fact that some authors (Lavrov et al) state that a gauge theory with softly broken BRST symmetry is ...
- 352
1
vote
0
answers
59
views
Spontaneous Symmetry Breaking vs Addition of 'Mass terms' by hand [duplicate]
Let consider an $SU(2)$ doublet of bosons $\Phi =(\phi_A, \phi_B)$
which is described by the Lagrangian
$$L = (\partial_{\mu}\Phi)^{\dagger}(\partial_{\mu}\Phi) +a^2 V(\Phi^{\dagger} \Phi)
-\frac{\...
- 1,395
1
vote
0
answers
67
views
Gauge cosmic strings and large gauge transformations
I've been going around in circles (hah) about how gauged cosmic strings work (I've been using Preskill's notes for the most part). The global string scenario makes sense to me, since different points ...
- 143