Talk:Color confinement

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Force[edit]

"Thus the force experienced by the quark remains constant regardless of its distance from the other quark. Since energy goes as force times distance, the total energy increases linearly with distance."

I was under the impression that gluons are represented as springs in Feynman diagrams because the force felt between two quarks roughly follows Hooke's Law F = -kx (or F = kx if k is taken to be negative) and so is roughly proportional to some constant times the distance. This would obviously mean that U = (+/-)kx^2, or that the total energy increases quadratically with distance. Am I incorrect in this impression? Or would someone with greater experience correct this? (August 23, 4:49 pm UCT)

The article is correct. See (for example, just randomly) the recent paper QCD potential as a "Coulomb-plus-linear" potential -- Xerxes 02:42, 2004 Aug 24 (UTC)
More intuitive: The energy stored in a flux tube between two (static) quarks doubles as one doubles the distance between the two quarks (neglecting a possible "string breaking"), hence the force is constant. There is no such a "internal" structure as in a spring. A string is almost a spring, but just almost :-) --129.132.1.35 10:02, 1 Sep 2004 (UTC)
Nobody answered this person's question, the question again is, "Am I incorrect in this impression?" His alternative question followed from that, and that question is, " Or would someone with greater experience correct this?" - 'this' refers to the person's impression of the article, not the correctness of the article, and not your impression of the article. The article in wikipedia says, "Thus the force experienced by the quark remains constant regardless of its distance from the other quark." - regardless of distance???? That is simply wrong. Because the force depends on the distance (if it is small, large, or something in between). I'm going to see if I can word things better than they currently are.Kmarinas86 22:33, 28 June 2006 (UTC)

Contradictions ! - Color confinment is an illusion.[edit]

... color charged particles (such as quarks) cannot be isolated singularly ... When two quarks become separated, as happens in particle accelerator collisions ...

What is the meaning of the word separation ? Acting separately ? Having distinct properies ? Or exist separately at some greater distance ? What is the distance constraint ? What is the action constraint ? What is the concept of separation in QCD ? If some force is strong, an you are not able to separate constituents, does it mean total confinment ? Maybe confinment of thinking. In nuclear particle interactions, quarks are changed or exchanged, according to the main stream theories. What is the cause of effect in interactions, if color force prohibts quark separation. If separation, or separate action, is possible, there is context of this separation and separate action. If it is not, the meaning of the quark is redundant, because it is just effect of other, more fundamental entity, and quark is a view of that entity. What is the size of the quark ? Where is the boundary of "cannot be isolated singularly" and "two quarks become separated" ? Does the QCD theory do not recognize the time and space scales ? Do the word "detected" means "detected by human detectors" or "exist as real entity in nature" ? Color confinment is an illusion. Color confinment violates both, the causality and energy conservation. If color force "is constant, and does not decrease with increasing distance", where did the energy for this come from ? What is the integral of such force of particle ? Is color force isotropic ? Color confinment means deterministic creation of quark-antiquark pairs. The speed of this creation must deterministicaly reflect the relative speed of quark-quark, in both directions. That means controling the quark-antiquark creation and annihilation. And we are back. What are conditions for the dynamics of quark-antiquark creation and annihilation ? What is stability of such structures ? What if some quark-antiquark in chain annihilates sooner than the cause causes the anticause ? The state of the cause (quarks) is instantly interconnected with the state in the space between the quarks. What is the spacetime layout of such structures, especially in the context of quark motion at relativistic speeds. Total violation of causality ! Is this physics or Lego for children ? Pardon - Lego is causal ... Softvision (talk) 00:10, 14 July 2009 (UTC)

Confining 'phase'[edit]

What does 'confining phase' mean in following excerpt? not understandable to even lay physicist. Wilson loop is ok since there is a link.

"The confining phase is usually defined by the behavior of the action of the Wilson loop" —Preceding unsigned comment added by 134.174.140.104 (talk) 18:51, 2 February 2009 (UTC)

strange matter[edit]

Wouldn't something like strange matter violate confinement? -- Natalinasmpf 12:15, 5 November 2005 (UTC)

No, strange matter has extremely high density. Confinement restricts how far quarks can move away from one another. Strange matter has so many quarks in so little space that they do not need to move far from one another. -- Xerxes 17:59, 5 November 2005 (UTC)

mistake[edit]

Something is wrong here:

> Thus the force experienced by the quark remains constant regardless of its distance from the other quark.

> The force between quarks increases as the distance between them increases, so no quarks can be found individually.

One of these statements is wrong. Which one?

They're both correct at different scales. As quarks separate, the force between them initially increases and then becomes constant. Could be worded more clearly perhaps. -- Xerxes 22:12, 13 December 2005 (UTC)
I've heard that, at some range, the attractive force between quarks increases linearly with distance (i.e. ). However, when that is true, that would mean that force*distance would be quadratic in nature, like elastic potential energy (i.e. ). In contradiction to this, there is the coloumb+linear potential, which does not appear to have the property of linearly increasing force. [[1]] In fact, the decreasing of the slope in the line graph of such a potential, suggests to this layman that force decreases with distance (which is obviously wrong). [[2]] Somebody please clarify this...Kmarinas86 21:54, 28 June 2006 (UTC)
This article, the quarkonium article and the linked images indicating Coulomb plus linear are correct. -- Xerxes 22:29, 28 June 2006 (UTC)
Explain to me how the slope for positive potential decreases with distance r (as in -1/r+r) and yet the force be increasing or remain constant. This is what I don't get. A binding force which is increasing with distance will imply a binding energy which increases with distance in a non-linear increasing-slope fashion, whereas a binding force constant with distance will have a linearly increasing binding energy. I thought potential and energy are very related. Is it the case the potential and energy are not proportional? I've never heard of such. Why is the term "binding energy" avoided and/or not used in the case of confinement. What is with the confusion between linearly increasing force and linearly increasing energy as distance increases linearly? Why do some interested people even have to be confused about this, when things are supposed to be said in a straightforward manner? Why do many people have the impression of "spring constants" even if they are aware that there exists a difference between a "string constant" and a "spring constant" Please answer the questions, only if you can explicity, thanks...Kmarinas86 23:12, 28 June 2006 (UTC)
Why do people write like that? Concerning these two sentences, difference in context is indistinguishable as far this this single article is concerned, thus the statements, though correct according to some, are contradictory. Why can't they just say it in a more straightforward manner that doesn't look like a hodge podge? This is ample proof that the article is not clear as it ought to be. Show me the formula that corresponds to the force which increases directly proportional to energy AND distance simulatanously. If you tell me that force and energy are the same quality in the context of the "linearly increasing" nature of the confinement, you'll make absoultely no sense to me, unless you back your claims.Kmarinas86 23:32, 28 June 2006 (UTC)
Of course the problem is that the analitic expresion for this force has not been given anywhere yet, we have separate indications of asymptotic freedom (force decreasing fast at short distances) and confinement (huge force at large distance). Quarkonium is just a model (a good one) extracted from approximations to QCD, but no straigh QCD thing. Perhaps a detailed aricle should give some quantitative data from lattice simulations Arivero 07:17, 29 June 2006 (UTC)
On other hand, a string model of quarks has constant string tension, thus constant force. Arivero 07:24, 29 June 2006 (UTC)

I would like to point out the utterly erroneous claim, "The reasons for quark confinement are somewhat complicated; no analytic proof exists that quantum chromodynamics should be confining, but intuitively, confinement is due to the force-carrying gluons having color charge." This is wrong, confinement is predicted by the Yang-Mills field theories, which make up the Standard Model. I refer to page two of Georgi & Glashow's Phys. Rev. Lett., 32, 438 (1974) paper. http://link.aps.org/doi/10.1103/PhysRevLett.32.438 [[User:Elmoosecapitan[Elmoosecapitan]] 23:27, 16 Nov 2009 (CST) —Preceding unsigned comment added by Elmoosecapitan (talkcontribs)

Quark deconfinement now redirects here[edit]

Quark deconfinement (presumably referring to what happens in relativistic heavy ion collisions) now redirects here. Therefore it would probably be good to add a section on this topic. Any experts out there? HEL 02:16, 5 November 2006 (UTC)

Culled a confusing line[edit]

I removed the line "Not to be misunderstood with generic colours;Quarks exist much below visible spectrum" from the beginning of this article as it is confusing/misleading on several counts - there's no phenomenon of visible light termed 'colour confinement' and relating quarks to the visible spectrum is illucid at best (if it is trying to say that quarks don't interact with visible light) and flat out wrong at worst (if it's trying to say that quarks constitute some kind of electromagnetic radiation 'below' the visible spectrum, wherever that is). I believe the sentences that follow give sufficient context to the phenomenon of colour confinement as a QCD concept rather than an optic one that no forewarning is necessary. If someone stumbles onto this page with no previous knowledge of QCD, links to quark and color charge are immediately available. Eutactic (talk) 03:50, 21 July 2008 (UTC)

{{reqdiagram}}[edit]

Hi, a diagram was added to the article after this template was added. So I am removing this template for now. If you think another diagram is needed, please re-add the template with some specific details about what kind of diagram. thanks --pfctdayelise (talk) 10:04, 27 July 2008 (UTC)

Nothing else but a number of postulates[edit]

The confinement is in fact nothing else but the postulate, that quarks (including anti matter) always occur in combinations of two or three quarks, so that the charge is an integer multiple of the elementary charge. --84.59.225.126 (talk) 15:40, 25 October 2008 (UTC)

From the fact that all objects observed in nature have an integer multiple of the elementary charge, the postulate is required to avoid an obvious contradiction with observation. --84.59.241.92 (talk) 16:05, 25 October 2008 (UTC)
Yes, but that means the statement that quarks (including anti matter) always occur in combinations of two or three quarks, so that the charge is an integer multiple of the elementary charge, is not a postulate, but a necessary consequence of observation. Indeed the confinement is in fact nothing else but the postulate, that quarks (including anti matter) always occur in combinations of two or three quarks due to their color charge and particles called gluons, so that the electric charge is an integer multiple of the elementary charge and no free particles with a color charge or free gluons exist. These are actually a number of postulates, that are not really evident. --84.59.248.202 (talk) 18:36, 25 October 2008 (UTC)
It is well known, since about 100 years, that the electric charges of all objects observed in nature are an integer multiple of the elementary charge e. Therefore, the 12 free quarks with ±2/3e and ±1/3e cannot exist as free particles. Even accepting the postulate, that the quarks can only exist as bound states combining two or three quarks, it is still not at all clear, why all objects observed in nature carry an integer multiple of the elementary charge e. At least two addional postulates are required, saying that never two of the six matter or two of the six anti matter quarks occur in a meson and that a baryon never contains a matter and an anti matter quark at the same time. Moreover, it is not clear why quarks are always combined to two or three quarks and never four, five or more quarks. --84.59.250.117 (talk) 09:11, 30 October 2008 (UTC)

The elementary charge?[edit]

If we believe in theory, the real elementary charge is not the charge of the proton but the charge of the down quark, since its charge is in fact the smallest unit of charge that occurs in nature and all charged particles in nature carry an integer multiple of that charge. Ordinary matter then consists of quarks carrying the charges one and minus two. Using these more natural units it becomes more obvious, that indeed all combinations of two quarks carrying an integer multiple of 3 are exactly the combinations of an ordinary quark with an antimatter quark. Moreover it is also fairly easy to see, that all combination of three ordinary quarks and all combinations of antimatter quarks are charged by a multiple of three. First this is obvious for three identical quarks and by exchanging up and down the charge changes by three. All other combinations of three quarks don't have a mutiple of three. —Preceding unsigned comment added by 95.222.228.77 (talk) 10:11, 4 December 2009 (UTC)

Ok, now we see that the proton has charge -3, the electron charge 3 and all free particles, matter and antimatter that ever have been observed carry the charges …, -12, -9, -6, -3, 0, 3, 6, 9, 12, … But, why? The theory tries to explain that by colour charges. But still, why colour charges allow only multiples of three? I can't see any reason. --95.222.228.77 (talk) 10:55, 4 December 2009 (UTC)

OPINION[edit]

I think we haven't found single quarks simply because we do not have the technology...yet. —Preceding unsigned comment added by 71.171.132.208 (talk) 22:08, 15 September 2009 (UTC)

I think we haven't found single quarks simply because quarks do not exist. --95.222.228.77 (talk) 13:04, 4 December 2009 (UTC)

major contradiction[edit]

the statemnt "...at some point it is more energetically favorable for a new quark/anti-quark pair to spontaneously appear out of the vacuum, than to allow the quarks to separate further." is wrong. Matter CANNOT be created (appear out of the vacuum) or destroyed. —Preceding unsigned comment added by 71.171.132.208 (talk) 22:15, 15 September 2009 (UTC)

Yes it can, see pair creation. Headbomb {ταλκκοντριβς – WP Physics} 22:45, 15 September 2009 (UTC)
ONLY IF there is ENOUGH ENERGY. If there is not enough then only a single quark should form, correct?
Not really. What happens in pair creation is that things are created in pairs of particles and antiparticles. Particles and antiparticles have the same mass, so if you want to create a pair of bottom quarks and antiquarks, then you need to to have (at least) twice the mass energy of bottom quarks. Bottom quarks have a mass of ~4200 MeV/c2, so you need a gluon (or photon, or Z0 boson) of at least 8400 MeV/c2 of energy to create them. If you don't have that energy, say you have only 2800 MeV/c2, then you can't create that pair of bottom quarks and antiquarks. But you can create other pairs, such as pairs of electrons and antielectrons, since twice the mass of an electron is ~1.022 MeV/c2, or a pair of charm quarks, since twice the mass of a charm quark is ~2500 MeV/c2. But it will never only produce only one of the two particle or antiparticle, since that violates conservation laws (specifically, the conservation of baryon number). Headbomb {ταλκκοντριβς – WP Physics} 21:51, 17 September 2009 (UTC)
The point is that it costs more energy to separate the quarks past a certain point, and less energy to create a quark/antiquark pair. So if you put enough energy into the system, instead of tearing the quarks apart any farther, the extra energy is used to create a quark/antiquark pair instead.—Tetracube (talk) 21:55, 17 September 2009 (UTC)
The charge is conserved, that is a fundamental law of physics. Think of single quark of charge 1/3e, -1/3e, 2/3e or -2/3e carrying no multiple integer of the elementary charge. All kind of interaction, pair creation or any interaction with leptons and hadrons or radiation will not change that. But such charges have never been observed. --95.222.228.77 (talk) 17:41, 4 December 2009 (UTC)
That means, if a single quark or any combination with non-integer charge is once created and separated where always will be a particle with an non-integer charge in all kind of reactions with ordinary matter or antimatter. It means such charges must have been observed at Fermilab or CERN. —Preceding unsigned comment added by 95.222.228.77 (talk) 09:59, 5 December 2009 (UTC)

Dont LHCs prove that protons can be broken apart therefore seperating quarks? 70.253.128.214 (talk) 05:34, 3 February 2010 (UTC)

Quarks are not made to go by themselves as far as I know. The smallest number of quarks observed so far is two.Kmarinas86 (Expert Sectioneer of Wikipedia) 19+9+14 + karma = 19+9+14 + talk = 86 15:21, 14 December 2010 (UTC)

Is this correct ?[edit]

OK, this is bound to completely wrong but maybe somebody can point out why. Imagine we have 2 electrons, each one is radiating (virtual) photons in all directions. If a photon hits another electron it gets absorbed, and then another photon is emitted back to the original electron. The net result is some momentum is transferred from one electron to the other, thus pushing them apart. Since the photons radiate in all directions, this force falls off as the surface of the sphere, ie 1/r**2. Now it seems that colour charge does not fall off like this, so it would appear that each quark "remembers" the direction of its target and only sends gluons in that direction. Hence the colour charge does not fall off like electric charge. The two quarks are exchanging gluons and anti-gluons (with negative momentum) so there is no net momentum change. Now we can imagine, that as a gluon travels, it has a probability of transforming into another quark and an anti-gluon. Thus, the further it moves, the higher probability of this ocurring. Hence if the two quarks are far apart, the probability is high - the gluon then turns into another quark, and an anti-gluon which returns to its origin. The result is what we observe, that a new quark is created, and no change in momentum of the original quark. —Preceding unsigned comment added by Salsa man (talkcontribs) 19:13, 20 March 2010 (UTC)

Information left out regarding application to mesons[edit]

The article explains why color confinement prevents quarks from being separated, but not why mesons can only be made of a quark and an antiquark.ZFT (talk) 22:56, 22 July 2012 (UTC)

Neutrino flow and proton-neutron neutrino change vs existance of free quarks[edit]

Well. Protons turn into neutrons and vice versa with positron electron emittance involving a neutrino. The mass of the proton is smaller than that of the neutron, so the electron emission of the neutron to become proton seems natural. And, the neutron is unstable. And ther is a neutrino involved. So I assume the neutrino forms a massy band around the proton, such that an electron can be confined within the space. As the quarks have never been detected but describe theory well, their existance might be artefact. However, the Sun neutrino density of 100 neutrinos per square centimeter http://hyperphysics.phy-astr.gsu.edu\hbase\particles\neutrino.html , with an average speed of almost light speed, a collision experiment might result in a immediate reaction of neutrinos from free space. Also, the conv3ersion reaction of e+ e- p n would cause immediate reaction. We know of free space that large photons cause e+e- formations or neutrino antineutrino? formations. Hence, a large energy like a free quark causes immediate e- e+ or neutrino pair formation from space itself, annihilating the free quark. As it seems, the mass of particles in microspace is larger the smaller the structure they consist of. To the structure of a proton: Could it be that two quark particles form a stable oscillator band with a neutrino forming the mass band, and the third particle (e.g. the positron) oscillating on that band, whereas a neutron is a pure oscillation of two particles and an empty band? would it be possible to take protons in a electric cage, neutrons in a magnetic cage, and measure the inner Vibration frequency of the object ? I guess it must be possible to resonate to the proton/neutron inner frequencies according to resonator theory, iff the resonator is just close enough. Means, there Has to be a reaction between a photon and a proton if the frequencies are matched, resembling the inner oscillation. and as far as i know, there is. Gamma quants Do decompose the photon on certain frequencies. So, can Someone run a Spectroscopy of that photons starting with XRay to Gamma ? do we have an xray spectrometer capable of running into Gammas ? Please forward to Cern. This Method is Based on First detection of inner resonances. Not on collission. Can be done on ALL Particles. And is an investigation method. Of course the wave needs to be produced, not the photon particle, using a laser micro stream. such a micro laser would need to be approximated with care. then see reaction. Will forward this to Cern. quarks and neutrinos and e- e+ form a reactive system. How come e- are Not formed of quarks but emerge from proton/neutrons on neutrino reaction ? I assume e- e+ are part of neutrons /protons, explaining the preference of matter to antimatter, as protons form atoms. neutrons are part of it. and all e+ are absorbed from neutrons to form protons. But e- form atoms with protons. --Wikistallion (talk) 09:17, 21 March 2013 (UTC)

Rubber band comparison[edit]

I think the rubber band comparison is a little misleading. The force in a rubber band is proportional to its extension, whereas the force between two quarks is independent of the distance between them. — Preceding unsigned comment added by 92.20.145.180 (talk) 17:35, 19 May 2015 (UTC)

160,000 or 10,000 Newtons?[edit]

Color confinement “Because of this behavior of the gluon field, a strong force between the quark pair acts constantly—regardless of their distance—with a strength of around 160,000 newtons, roughly the weight of three elephants.”

Strong interaction: "After a limiting distance (about the size of a hadron) has been reached, it remains at a strength of about 10,000 newtons, no matter how much farther the distance between the quarks."Antonquery (talk) 03:38, 10 August 2015 (UTC)

Proposal to merge QCD string into Color confinement[edit]

The QCD string article has been a sad little stub for the past 12 years. Its content should fit well within the Color confinement article, without causing any problems related to article size or undue weight. David Schaich Talk/Cont 17:39, 3 August 2017 (UTC)

Agree on the merge. I don't see QCD string is going anywhere. --Ciphers (talk) 19:45, 3 August 2017 (UTC)