Questions tagged [confinement]

Color confinement is the concept that particles that possess color charges (quarks and glouns) can not be found freely, and only color-free combinations can be observed.

Filter by
Sorted by
Tagged with
3
votes
5answers
74 views

How does the mere movement of gluons keep quarks together?

You know the strong force (the one that keeps quarks together). Well it works by exchanging gluons right? So how does that force keep the quarks together? I mean you can imagine that process as three ...
2
votes
1answer
47 views

What happens when one separates a quark-antiquark pair?

in particular, if the distance is more than about 1 fm?
1
vote
0answers
27 views

In a Big Rip scenario, would color confinement cause a singularity to form?

The energy in a gluon tube between quarks increases approximately linearly with the distance between them, and when that energy is sufficient to spawn a quark-antiquark pair out of the vacuum, it does ...
1
vote
0answers
60 views

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
votes
3answers
108 views

Why quarks are confined? Why can't they be found in unbound states?

No one has observed before a "free" quark, i.e. a quark in an unbound state. According to one paper, I read that $p\bar{p}$ collision produce unbound $t\bar{t}$ pair which quickly decay into ...
0
votes
0answers
14 views

Can a baryon consist of two quarks and an antiquark? Or a pentaquark be made of three quarks and two antiquarks? [duplicate]

I suspect these particles exist, but are extremely short-lived, even compared to other unstable, exotic particles...
6
votes
0answers
114 views

Validity of Seiberg-Witten theory and the understanding of notion “Effective field theory”

I am reading "An Introduction to the Confinement Problem" book by Jeff Greensite https://books.google.ru/books?id=atwRBwAAQBAJ&printsec=frontcover&hl=ru#v=onepage&q&f=false, ...
0
votes
1answer
40 views

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
vote
2answers
39 views

Permitted bound states in extended QCD color group $SU(4)$

I'm very much curious about the possible quark combinations to form bound states in $SU(4)$ QCD. We already know Wilson has proven that only colorless combinations can arise in $SU(3)$ of these ...
3
votes
0answers
81 views

Abelian theory with confiment in 4d (Polyakov book)

In chapter 4.3 of Gauge Fields and Strings Polyakov study effect of monopoles. He make few statements: In 4d Maxwell theory with monopoles, exist phase transition, if $e_0^2> e_c^2$ it is ...
3
votes
2answers
58 views

At the Big Bang, when particles were created, could free standing quarks (not bound in a hadron) have been created and remain alone today?

You can't pull a quark out of a hadron, but at time $T = 10^{-43}$ seconds or shortly thereafter, when all particles were created, wouldn't all quarks be individual, and not grouped into hadrons, (...
1
vote
0answers
73 views

Phase transition in 3+1 abelian theory

In historical paper A View From the Island, A. M. Polyakov wrote at 6th page: In the abelian case, these dislocations turned to be just the world lines of magnetic monopoles and I predicted the ...
2
votes
0answers
29 views

Models of confinement based on negative mass carriers

In the old Yukawa model of nuclear forces, it was proposed that short-range interactions were mediated by exchanges using massive force carriers (originally, mesons were proposed for this). If one ...
6
votes
1answer
201 views

Simple “toy-model”-like explanation of quark confinement (QCD) and accompanying math

I have a qualitative understanding of quantum chromodynamics within nucleons and between nucleons, but I do not understand the math behind some of the physics like quark confinement. What is the math ...
2
votes
0answers
45 views

Quark confinement mechanism

As far as I understood: Quark confinement states that observing individual quarks is not possible, color charged quarks are confined into hadrons. As we try to pull them apart, force between them ...
0
votes
0answers
27 views

Is it possible to derive a non-mass gap from the Yang-Mills action? [duplicate]

The action: $$J=∫Tr(F∧⋆F).$$ Is it possible to find the non-mass gap property from the Yang mills action? If so, how?
0
votes
1answer
64 views

What is quark 'confinement' in the context of Yang-Mills Theory?

In the context of Yang Mills Theory, what is quark confinement? Please try to explain as simple as possible (obviously without being too general)
0
votes
0answers
66 views

Why there is no such a thing as colour moment?

I was busy google about different types of electric and magnetic dipole moment then a thought suddenly striked me, why there is no colour multipole moment?
4
votes
2answers
2k views

Why hasn't Peter Higgs solved the Yang-Mills prize problem?

The Higgs mechanism gets rid of the mass gap problem, and it's been experimentally proven, so why is there still a problem? Why are the million dollars still up for grabs?
1
vote
2answers
82 views

Can particle with fractional charge exist in isolation?

Since quarks are ruled out I wonder if it is possible for free fractional charge to exist not counting virtual particles?
1
vote
0answers
46 views

What happens when somebody solved mass gap problem like ultraviolet catastrophe? [closed]

Just curious if somebody came along and proposed a good mathematical solution to the millennium problem but it is not intuitive at first, what happens then? this person can rigorously proof the ...
1
vote
1answer
93 views

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, ...
3
votes
1answer
107 views

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
votes
1answer
199 views

Why do we still call the electron charge the elementary (EM) charge?

The electron is an elementary particle, part of the SM, pointlike, with no substructure, or spatial extent. Its intrinsic properties include its EM charge, which we still call the elementary charge. ...
3
votes
1answer
86 views

How are quarks assigned color charge?

As always, I'll preface that I am wildly undereducated, so i may be overlooking something or be completely unaware of another relevant property. Color Confinement dictates that to "assemble" a baryon ...
1
vote
1answer
56 views

Asymptotic freedom and momentum exchange

Why is the momentum exchange very high for low distances? For sufficiently short distances or large exchanges of momentum https://en.wikipedia.org/wiki/Asymptotic_freedom While I think about ...
1
vote
2answers
157 views

Why do mesons decay?

Why do mesons decay shortly while baryons are more stable? And why do mesons decay, meaning that there are unstable, while they formed because meson is more stable than the two corresponding quarks? ...
5
votes
1answer
301 views

If quarks don't exist individually how can we say baryons are made up of three quarks?

We know the composite subatomic particles are made up of odd number of quarks (at least 3 for baryons ) or combination of quarks and antiquarks (mesons). My question is if they don't exist ...
1
vote
0answers
24 views

Below which energy would the weak interaction become confining?

Claudson et al considered an alternative formulation of the standard model where the SU(2) interaction was strengthened to become confining below ≈ 300 GeV, above the electroweak scale. Consider if ...
5
votes
1answer
87 views

Would Color Confinement apply in higher dimensions?

As I understand it color confinement comes from the fact that as the distance between two color charges increases the color potential energy increases, instead of decreasing, and the energy needed to ...
1
vote
1answer
52 views

Why do we have 3 quantum colours?

I understand the need to invoke colour as another quantum state to explain the observation of uuu ddd and sss baryons. I just wanted to know if there was some other property which explains why we only ...
7
votes
2answers
160 views

Why does the divergence of a QFT's coupling constant under RG flow trivialize the theory if it occurs in the UV but not in the IR?

When you first learn quantum field theory, at some point you calculate the beta function (to leading order) for a renormalizable coupling constant of some theory like $\varphi^4$ theory, Yukawa theory,...
0
votes
3answers
117 views

Can a quark quantum tunnel outside a nucleus?

I read that a particle wavefunction can extend over a thin barrier and there is a probability of finding it over the barrier even though it doesn't have the necessary energy, what about quark?
3
votes
1answer
64 views

How and why is the pentaquark stable if it consists of 4 quarks and an antiquark?

If matter and antimatter annihilate each other, why is the pentaquark stable since quarks are matter and the antiquark is antimatter?
0
votes
0answers
40 views

Why are mesons only made of a quark-antiquark pair? [duplicate]

Why can't we have a meson made of two quarks, why does there have to be the antiquark too?
0
votes
1answer
86 views

Clarification about confinement of colour charged objects

In lecture today we were reviewing the QCD lagrangian, and discussing hadronic wavefunctions. My lecturer said that QCD alone allows for states of colored hadrons, however because we do not see ...
3
votes
2answers
171 views

Spaghettification on quarks?

Imagine a nucleon falls into a black hole, I would expect the gravitational force acting on each quark to be drastically different but due colour confinement wouldn't there more pairs of quarks being ...
0
votes
0answers
219 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 ...
3
votes
0answers
74 views

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, ...
3
votes
2answers
980 views

How do we know that gluons travel at the speed of light?

Since gluons are located within nucleons and immediately outside of them, how do experiments determine parameters like their speed? Is it possible we could be assuming they travel at the speed of ...
1
vote
0answers
144 views

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 ...
4
votes
1answer
200 views

How to “build” a proton

Sabine Hossenfelder in her column The End of Theoretical Physics As We Know It made the following statement: For example, we have a perfectly fine theory that describes the elementary particles ...
1
vote
2answers
492 views

Can we find a free gluon?

I have read these questions: Quark intrinsic angular momentum and the Proton Spin Crisis About free quarks and confinement https://en.wikipedia.org/wiki/Gluon And it made me curious. I understand ...
0
votes
1answer
65 views

Difference between boundedness (electrons around nuclei) and color confinement (quarks)

I have read these questions: How does the orbiting of electrons around nuclei START? Bound electrons don't move, right? Do different orbitals overlap in multielectron atom? What is the difference ...
1
vote
1answer
46 views

How does it make sense to talk about, for instance, quarks traveling at near lightspeed while confined to a volume as small as a proton?

How does it make sense to talk about, for instance, quarks traveling at near lightspeed while confined to a volume as small as a proton? The distances are so small, and the speed so high, that the ...
0
votes
1answer
59 views

What happens if I add a single quark to a system of hadrons? [duplicate]

In pure QCD in the confinement phase what happens if I add to a system of baryons, which are quarks in the condensed phase, another quark? It doesn't have any quark or antiquark to form a baryon or a ...
4
votes
1answer
280 views

Is there confinement in the Gross-Neveu model?

The Gross-Neveu model is a simple quantum field theory in 2 space-time dimensions that is considered a toy model for QCD, in the sense that it realizes asymptotic freedom, chiral symmetry breaking ...
1
vote
0answers
235 views

Wilson Loops and Confinement in QED

In [1] Kenneth G. Wilson proposed a mechanism for confinement using lattice paths what leds him to the concept of Wilson loop. It seems to me that he is using mainly a single abelian field. He says ...
0
votes
1answer
169 views

Has experimental search for free fractional electric charge elementary particles been put to an end?

Since Quantum Chromo-Dynamics theory has been supposed to explain quarks confinement, has experimental search for free fractional electric charge elementary particles been put to an end? If not, what ...
2
votes
0answers
203 views

What's the meaning of QCD phase transition temperature?

I read about the QCD energy level in various sources, eg: Wikipedia, and this gives a phase transition temperature of about 200 MeV, above which quark confinement breaks down and we may observe ...