All Questions
Tagged with quantum-chromodynamics higgs
15
questions
2
votes
0
answers
73
views
How to update $SU(2)$ Higgs fields with Heat Bath algorithm?
I'm trying to update the Higgs field coupled with a pure gauge $SU(2)$ theory through Heat Bath algorithm. Pure gauge and Higgs configurations should be updated separately. For the pure gauge part the ...
- 31
1
vote
1
answer
122
views
What means Higgs branches in 5d?
I've been reading advanced string theory text but I came across with a paper that I definitely don't understand at all, what it means?, this text is Higgs branches of 5d rank-zero theories from
...
1
vote
0
answers
63
views
Can the process gluon + gluon $\rightarrow$ 2 Higgs proceed in the following way in the standard model?
At order $g_s^2$, usually only a triangle quark loop and box diagram are considered, I was wondering, is there some reason that excludes these diagrams from the possible standard model channels?
0
votes
1
answer
55
views
How is the difference in ground and excited state of baryons masses explained within QCD and SM?
How is the difference in ground and excited state of baryons masses ($\Sigma$ and $\Sigma^*$, $\Xi$ and $\Xi^*$ for example) explained within QCD and SM? Is it possible to calculate (predict) this ...
- 649
2
votes
1
answer
326
views
What corresponds to the radial component of the axion potential?
An axion can be understood as an oscillation of the axion field in some potential.
In the Higgs mechanism, there are 4 degrees of freedom. The Higgs boson is the radial oscillation and 3 remaining ...
- 175
1
vote
1
answer
137
views
How do I calculate the amplitude of an $s$-channel Feynman diagram?
What is is the starting point to measure the amplitude in an $s$-diagram like the one below where two particles collide and create a propagator followed by the final product?
I know that in $t$-...
user256673
0
votes
0
answers
74
views
What is the meaning of the structure constant for the $\rm SU(3)$ group and how I can find its values? [duplicate]
To calculate the tree-level amplitude for:
$$Z(p_1) + Z(p_2) \to Z(p_3) +Z(p_4)$$
I must take into the consideration, amongst other cases, the amplitude for:
I know the values shown in another post ...
user256673
0
votes
1
answer
95
views
How do I find the values for the structure constants ($f^{abc}$) of a gauge group?
How do I find the values for the structure constants ($f^{abc}$) of a gauge group, as a mean to find the tree-level amplitude for a process in which one of the tree-level diagrams is:
the process ...
- 753
0
votes
2
answers
350
views
About the mass of the particles
Studying Higgs mechanism in EW theory and QCD I have a couple of questions that I would like to clarify:
1) The quark mass term in QCD Lagrangian should come from Higgs mechanism in EW sector of SM. ...
- 1,597
10
votes
3
answers
2k
views
How much of the proton's mass is due to the Higgs field?
The proton mass is 938 MeV. People often claim that
(A) The proton is a bound state of two up quarks and one down quark, with the three quarks contributing a total rest mass of $2 \times (2.2 \text{...
- 48.4k
4
votes
0
answers
512
views
Beta function for non-Abelian gauge theory with both fermionic and bosonic matter fields
Consider a non-Abelian gauge theory with both fermionic $\psi$ and bosonic $\phi$ matter fields in 4D, which may be called a QCD-Higgs model,
$$L=-\frac{1}{4 g^2}F_{\mu\nu}F^{\mu\nu}+\bar{\psi}i\gamma^...
- 11.9k
26
votes
1
answer
2k
views
Why we don't have macroscopic fields of Higgs bosons or gluons?
Why is it that there exists a classical macroscopic field of photons and gravitons but not that of $Z, W^{\pm}$ bosons, gluons or Higgs boson?
user133658
8
votes
1
answer
1k
views
Is Higgs mechanism necessary in QCD?
As we know, the Higgs mechanism is introduced in the Standard model in order to explain the masses of the gauge bosons, the leptons and the neutrinos (maybe?). The Higgs mechanism is necessary to ...
- 83
4
votes
1
answer
344
views
should the Z0 decay at the same rate that the neutral pion?
The original title of the question was "In a composite Higgs..." and so the sub-questions were done around this theme: Should the decay rate of Z0 be related to the decay of the "higgs" composite ...
- 1,943
13
votes
2
answers
3k
views
The contribution to mass from the dynamical breaking of chiral symmetry
The claim is often made that the discovery of the Higgs boson will give us information about the origin of mass. However, the bare masses of the up and down quarks are only around 5 MeV, quite a bit ...
- 131