All Questions
28
questions
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55
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A list of failed attempts towards a proof of confinement [closed]
Can one give a list of failed or open attempts (not necessarily Supersymmetric) towards a proof of confinement in 4d regarding YM or QCD?
- 1,268
6
votes
1
answer
130
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How to avoid the ordinary Coulomb solution in QCD?
To see where QCD starts to differ from the behavior of EM fields, we might begin by looking at the classical field. A search brings up
[question 339978] and [question 360061] but no answer is found ...
- 4,912
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votes
1
answer
81
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Possible cases of matter fields for $SU(2)$ theory which retains asymptotic freedom?
Let us assume $4$ spacetime dimensions.
QCD, the $SU(3)$ gauge theory with quarks as the matter fields, have the asymptotic freedom property as long as there are 16 quark flavors of mass below the ...
- 1,669
3
votes
2
answers
161
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How do we known that $\langle \bar{\psi}_i \psi_j\rangle=(250 MeV)^3\delta_{ij}$?
I have started to read the phenomenology of QCD in low energy regime. I understand that, from the QCD renormalization group equation, the QCD becomes nonperturbative theory when energy scale is below $...
- 31
4
votes
1
answer
214
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How does AdS/CFT help us understand non-perturbative aspects of QCD?
I've heard AdS/CFT has found applications in many areas of physics where nonperturbative aspects leave us crippled in making any simple calculations.
Among these applications, I also have heard that ...
- 1,268
7
votes
1
answer
207
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With enough fermions, does QCD confinement disappear?
It's been a while since I thought about QFT, but the following thing was puzzling me. I've often read that theories with a beta function that is asymptotically free at lowest order will likely suffer ...
- 2,292
9
votes
1
answer
1k
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What is confinement?
I just got confused about the meaning of confinement in QFT.
The naive definition is that in QCD one cannot observe isolated quarks and gluons. This is a trivial statement because in any gauge theory ...
1
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0
answers
87
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In the deconfinement phase, there are absolutely no interactions between the particles?
The Wikipedia article on Deconfinement says: "In physics, deconfinement (in contrast to confinement) is a phase of matter in which certain particles are allowed to exist as free excitations, ...
- 956
2
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0
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783
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QCD energy scale $\Lambda_{\rm MS} $, $\Lambda_{\rm QCD}$, ...?
Why there seems to be different conventions of QCD energy scales? Is that due to the running coupling?
For example in Wikipedia https://en.wikipedia.org/wiki/Coupling_constant#QCD_scale:
$$
\Lambda_{\...
- 4,336
0
votes
1
answer
108
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Can a gauge theory with $SU(2)_{left}*SU(2)_{additional}$ symmetry contain confinement?
Consider a gauge theory with $SU(2)_{left}*SU(2)_{additional}$ symmetry.
By $additional$, I mean adding a new symmetry between an electron and a quark(like up quark and electron forming a doublet).
...
- 1,268
1
vote
1
answer
157
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How do you reconcile quark masses with notion of confinement?
In trying to understand exactly what confinement means, I have been reading 't Hooft s original paper on 2D QCD at large $N$. In the paper he shows that the quark propagator pole is moved to infinity, ...
- 744
5
votes
1
answer
375
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How can we tell a theory is confining?
Physically, I understand what it means for a theory to be confining. The elementary particles are not observable, but only composite particles are. The classic example is QCD, where quarks are ...
- 3,514
0
votes
0
answers
696
views
Why is color confinement a difficult problem?
Assuming color force follows a constant rule of force instead of an inverse square rule of force. And that red, green and blue are all attracted to each other.
Why is color confinement considered a ...
user84158
4
votes
0
answers
143
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What is the relation between the Gribov problem and color confinement?
I have heard that the Gribov problem is in some way related to color confinement (For instance: Gribov copies and confinement). Although I understand what both the Gribov and confinement problems are, ...
- 17.8k
1
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0
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178
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Four-fermion "contact" interactions differing from those arising from the Standard Model
In the 1998 article Compositeness Test at the FMC with Bhabha Scattering, it states that:
It was pointed out that the existence of quark and lepton substructure will be
signalled at energies well ...
