Confinement, Asymptotic Freedom and Other Phenomena

Some phenomena are successfully explained by QCD. Let us point out the most famous of them, which are considered as proof to the veracity of the QCD Theory.

Confinement and Asymptotic freedom
When protons are bombarded with high energy electron beams, two seemingly contradicting phenomena occur. On one hand, the quarks inside the proton seem free, i.e., their binding energy is very small compared to the energy of a highly energetic incident electron. One could therefore reasonably assume that if the incident electron’s energy is high enough, it could tear the quark off the proton. But experiments show that it is not possible to tear a single quark off the proton, even with highly energetic beams.

Both these phenomena, the asymptotic freedom and Confinement, are accounted for by QCD: the attraction force between quarks increases as they move away from one another. This idea explains both phenomena, but attributed to the Strong Interaction a characteristic which is opposite to what is known about basic natural laws of other forces. The question here is whether QCD’s explanation is the only possible one.

The phenomenon of the quark’s relative freedom with regard to the incident particle is known from the atomic model under the name of “The Compton Scattering”, which occurs when a high energy photon hits an atomic electron. The question is why is it impossible to tear the quark off the proton, whereas in the atom, a highly energetic photon is capable of tearing an electron off (i.e. to ionize the atom).

Comay’s explanation
The explanation suggested by Comay is based on well-known phenomena. It is established that when energetic electron beams hit the proton, nearly all the collisions are inelastic, that is, creating new particles.
It is also well established that when a particle meets its antiparticle, they annihilate one another and release energy in an amount equal to the sum of their masses. More precisely, this energy released is equal to the sum of the particle masses at the time of annihilation, which can be larger than their rest mass if they have kinetic energy, or smaller than their rest mass if they have binding energy.

The reverse process takes place in a similar way. In certain circumstances, a highly energetic particle can lead to the creation of a pair of particle- antiparticle, reducing the original particle’s energy by the amount of the energy of the newly created system. In the case of the proton, a meson is usually produces, i.e., a bound pair of quark-antiquark.

Pair creation and annihilation is a well known phenomenon in Physics. In the case of the electron – positron pair, the binding energy is very low compared to their mass, and the pair creation results in the outcome of free electron and positron. For quarks, binding energy is very high and consumes most of its self-mass, leading to the production of bound pairs, i.e. mesons.

What is going on inside a proton bombarded by electrons? When the quark gets hit and acquires a lot of energy, the interaction usually yields mesons composed of a quark-antiquark pair, reducing the energy of the target quark. If a single quark could be torn off the proton, its energy would most likely be in the order of thousands of MeV. But for the production of a meson, 140 MeV are enough. Therefore, the target quark ends up losing its energy into pair creation, rather than escape the proton. When a quark-antiquark pair is created, the energetic quark can associate to the antiquark of the pair. Furthermore, we know that the proton contains quark-antiquark pairs, which means that a quark hit by an electron can annex an antiquark, become a meson and get freely out of the proton.

This means that it is much easier for a single quark to create particle pairs by joining an antiquark in its vicinity within the proton, than to overcome the huge potential barrier created by the core’s attractive monopole field and escape the proton.

These phenomena can therefore be understood without QCD’s explanation of the asymptotic freedom and confinement, not to mention QCD’s rather artificial explanation (called “cutoff”) for the fact that “confinement” has to cease at a certain distance from the proton center.

The advantage of Comay’s explanation – why mesons are not confined in protons
QCD does not really provide a clear explanation why mesons created in energetic collisions can overcome “confinement” and exit the proton. The forces described by QCD should confine the newly created mesons to remain inside the proton. As far as we know, this question has never been discussed.

Comay’s explanation of this phenomenon is simple: mesons have a quark and an antiquark, each with an opposite magnetic charge, and therefore their total charge is zero. Since the Strong Interaction is a magnetic monopole force, it doesn’t attract a neutral pair that has a null magnetic charge and the meson is free to get out of the proton.

The three jets experiment
An interesting experiment of colliding high energy electron-positron beams was conducted at the PETRA labs. The collisions occasionally lead to the annihilation of these particles, producing a large amount of energy, which often prompts the creation of a new particle-antiparticle pair moving in opposite directions. This new pair can sometimes be a muon- antimuon pair, but sometimes a pair of quark- antiquark is created. Both the quark and the antiquark create particle jets, because of the action of the Strong Interaction on the quarks. QCD scientists predicted that occasionally 3 jets could be created, the third jet originating from a gluon. And indeed, these collisions did occasionally result in 3 particle jets [1].

Before we go on and see how this phenomenon is consistent with Comay’s model, we would like to draw the reader’s attention to the following point: in the literature, the fact that three-jet collisions are experimentally observed is considered as a major proof for the existence of gluons [2]. Since gluons do not exist as free particles, the only experimental evidence for their existence is necessarily indirect. Do the three jets created in an electron – positron collision constitute a sufficient and satisfactory proof for the existence of gluons, along with the entire QCD theory and its fantastic hypothesis? Do these experimental findings provide a good enough argument for the acceptance of QCD’s long series of contradictions, some of which are discussed in the present website?

There is a well-known process in Electromagnetism called “The Bremsstrahlung Radiation”, referring to the emission of photons during the interaction between electric charges. The Bremsstrahlung related to electric charges is relatively weak because it is proportional to the sixth power of the charge. (According to the unit system commonly used for calculations, the square of the electric charge is equal to 1/137). In general, QCD can be described as a hybrid of Electromagnetism and a highly complicated mathematical structure. QCD’s gluon, among others, is conceived as analog to the photon in Electromagnetism. QCD scientists have therefore transposed the Bremsstrahlung idea onto the QCD framework and used it to predict gluons emission.

On the other hand, the Bremsstrahlung effect does apply to Comay’s model. This process leads to the emission of an energetic photon, because the quarks are magnetic monopoles, the square of their magnetic charge is some 100 times stronger than the electric charge. Therefore, a magnetic monopole related Bremsstrahlung may take place, in a total analogy to the electric charge process in which a photon is emitted. Due to the larger elementary monopole unit, the photons are emitted with a much higher probability.

And this is the advantage of Comay’s explanation: it’s been known for over 50 years that energetic photons are involved in Strong Interactions – as we well remember from that inadequate explanation of the VMD theory. It is precisely these energetic photons that generate the third particle jet in the PETRA experiment.

Obviously, this result flows naturally from what is already known: the original Bremsstrahlung referred to photons, and we’re dealing with photons here too; the original phenomenon is based on electric charge equations, and here we’re talking about quarks which are magnetic monopoles, fulfilling equations which are analogous to Electromagnetism. In addition, energetic photons have been known since long to be involved in Strong Interactions, and therefore explaining this phenomenon does not require any new assumptions.

Additional phenomena
Some several independent Physics works associated to QCD have won Comay’s esteem, like for example Richard Feynmann’s and James Bjorken’s works, which lead to the 1969 SLAC experiments and provided additional proof for the existence of quarks that Comay considers as a good work with a major historical significance. As a matter of fact, the hadronic structure Comay proposes is founded on such quarks. Comay also considered the Drell-Yan process, sometimes attributed to QCD, as a good piece of work.

In order to invite physicists to draw their conclusions about the parts of QCD challenged by Comay’s model, here is a condensate of the basic principles underlying both models:

QCD is a physical theory derived from the QCD Lagrangian density. It is a (very complicated) extension of the Electromagnetic Theory to the Yang-Mills SU(3) group. Comay’s theory, on the other hand, suggests a dual structure of the Electromagnetic Theory, with magnetic monopoles (of a relatively large elementary unit charge) as charges. The system obeys to the Regular Charge- Monopole Theory and is derived from a Regular Lagrangian density[3,4].

[1] http://cerncourier.com/cws/article/cern/39747
[2] http://en.wikipedia.org/wiki/Gluon
[3] http://www.tau.ac.il/~elicomay/nc84.pdf
[4] http://www.tau.ac.il/~elicomay/nc95.pdf

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10 thoughts on “Confinement, Asymptotic Freedom and Other Phenomena

  1. Reply to anonymous (12 June 2012)

    In an energetic heavy ion collision a quite large number of pairs of nucleons collide within a small space-time region. Thus, the problem can be divided into two parts: nucleon-nucleon collision and interactions that involve products of such a collision.

    In my opinion, a theoretical prediction of the outcome of this process is a very difficult and untimely assignment. Therefore, I think that at present experimental physicists are the right people for undertaking this task. Let us wait and see if they find out new systematic effects of this process. In the following lines I try to briefly explain the reasons for my point of view.

    1. The proton is a highly relativistic system. The direct measurement showing that it contains antiquarks is a proof of this statement. Hence, methods of Quantum Field Theory should be used for its theoretical analysis. Furthermore, unlike electrodynamics where e^2=1/137, here the interaction strength is much stronger. For this reason, a Feynman diagram expansion is expected to converge much slower (if at all). Therefore, a theoretical calculation of this kind of problem is a very hard task.

    2. The difficulty of solving the problem of an energetic collision of heavy ions looks to me an order of magnitude more difficult than the high energy collision of two nucleons because it must analyze neither a single proton nor two colliding protons but also the interaction of the outcome of many colliding nucleons.

    3. Please note that in the simpler case of the proton-proton collision the explanation (see http://www.tau.ac.il/~elicomay/protonsc.pdf) of the cross-section is restricted to a limited aspect of the process; the total and the elastic cross-sections. Here one can take advantage of general laws of scattering. This approach cannot go too far in an analysis of an energetic heavy ion collision.

    A terminological comment: if you do not think that QCD is correct then it would have been clearer if you call the process “energetic heavy ion collision” and refrain from using the notion of gluon.

    • The following statements can be said about Quark-Gluon-Plasma.

      1. Gluons have no meaning outside QCD.

      2. The so called experimental evidence for a spin-1 gluon can be interpreted as photon participation in strong interactions. This property of the photon, which is known for about one half of a century, is naturally explained by the Regular Charge-Monopole Theory.

      3. This site and its associated book point out a plethora of different kinds of experimental QCD failures. Hence, there is no justification for a terminology that uses Quark-Gluon-Plasma.

      4. There is no theoretical reason for the QCD construction. For reading a proof of this point, see e.g. the following link and the reference therein: http://www.tau.ac.il/~elicomay/dpp_new.pdf

      5. BTW. The main point of the link mentioned above is included in a short paragraph. Can you or any other reader refute it? (It is a very short text and one cannot say that he or she have no time for reading it.)

      6. High energy proton-proton collision is certainly a simpler case than a high energy heavy ion collision. In the case of the proton-proton collision, QCD and its inherent asymptotic freedom cannot explain the rise of the total and the elastic cross sections (see p. 12 here: http://pdg.lbl.gov/2011/reviews/rpp2011-rev-cross-section-plots.pdf).

      7. A collision of two heavy ions is certainly a more complicated situation than a proton-proton collision. Let us wait and see if experiment can find out systematic results that are not seen in proton-proton collision.

      8. Like in any other case, one does not expect that an incorrect theory can provide meaningful results. Hence, it is not recommended that QCD be used in an analysis of the results of a heavy ion collision.

      • I do not defend QCD. I’d like to know how do you expect baryonic matter to behave at high energies and densities. Can be there, for example, an effect analogous to QCD’s deconfinement and can it lead to magnetic conductivity of this “monopole plasma”?

  2. A Reply to Shmuel Levine (May 11, 2012)

    The fact that quarks carry about one half of the momentum of a very energetic proton has been recognized about 40 years ago (see [1], p. 282). This evidence refers to the quarks that took part in the deep inelastic electron-proton scattering of that time, namely, the three valence quarks and the additional quark-antiquark pairs whose probability is not negligible.

    The notion of the baryonic core is defined here as “all other baryonic components that are not valence quarks or the additional quark-antiquark pairs”. In this sense, the baryonic core defers from the atomic nucleus, because in an atom, electron inner shells and the nucleus are well known as distinct objects whereas this is not the case for baryons. The following reason is used for this definition of the baryonic core: A discovery of baryonic elements depends on the energy used in experiments. Thus, if one wants to keep the baryonic analogy to the nucleus-atomic electrons then the definition of the baryonic core should be changed when more details of inner quark shells are detected by means of higher energy collisions. Please keep in mind that this definition of the core is just a terminology used in a discussion between people and it does not alter physics.

    Accepting this definition of the core, one realizes that it is electrically neutral. This conclusion is supported by the following argument. An electrically charged core will contribute to the elastic part of the electron-proton scattering and show up as an ordinary Mott scattering where the cross section decrease like 1/p^4 (see [1], p.192). The data tell us that the high energy elastic electron-proton cross section decreases like 1/p^6 (see [1], pp. 192-196). It means that the core is electrically neutral.

    Your argument concerning the charge of u,d quark is correct and one should keep it in mind when very high energy electron-proton experiments will be carried out. Evidently, in such experiments electrons are also expected to interact with individual quarks of the core’s closed shell. This effect will contribute to an increase of the number of events.

    [1] D. H. Perkins, Introduction to High Energy Physics, (Addison-Wesley, Menlo Park CA, 1987).

    • A theoretical element in the route to the recognition of the baryonic core is obtained from the equations of motion of the Regular Charge Monopole Theory (RCMT) [1] and their automatic explanation of the hard photon-nucleon scattering data (where proton and neutron look nearly alike). This issue shows that RCMT is relevant to hadrons. I think that all other properties should be derived from experiment.

      Thus, the three valence quarks and the fact that baryons are neutral with respect to the RCMT monopole charge indicate that the core carries three units of monopole charge whereas each quark carries one negative unit of monopole charge (the signs may be reversed). Further experimental data is needed for understanding the core’s structure.

      The energetic proton-proton scattering data published by PDG [2] help one make a further step. The rise of the elastic cross section at very high energy proves that the proton has a solid component that is able to take the heavy blow of the collision and keep the proton’s integrity. This effect indicates that the core has closed shells of quarks and that their existence is seen only in high enough energy. It makes sense to assume that the u,d quarks are more likely to be found in the closed shells and isospin symmetry indicates that at the core, the u,d quark population is the same.

      Let us hope that the upcoming LHC data will provide more information on this matter.

      A more detailed discussion on the RCMT relevance to hadrons can be found here [3]. An overview of this issue can be found here [4]. A discussion of the proton-proton scattering data of [2] can be found here [5].

      References:
      [1] E. Comay, Nuovo Cimento B80, 159 (1984). See: http://www.tau.ac.il/~elicomay/nc84.pdf
      [2] K. Nakamura et al. (Particle Data Group), J. Phys. G37, 075021 (2010). See p. 12 of
      http://pdg.lbl.gov/2010/reviews/rpp2010-rev-cross-section-plots.pdf
      [3] E. Comay, “A Regular Theory of Magnetic Monopoles and Its Implications”, in “Has the Last Word Been Said on Classical Electrodynamics?” ed. A. Chubykalo, V. Onoochin, A. Espinoza and R. Smirnov-Rueda (Rinton Press, Paramus, NJ, 2004). See: http://www.tau.ac.il/~elicomay/LastWord.pdf
      [4] http://www.tau.ac.il/~elicomay/OVERVIEW.html
      [5] E. Comay, PROGRESS IN PHYSICS, 2, 56 (2010). See: http://www.tau.ac.il/~elicomay/protonsc2.pdf

    • To summarize, we can say the following about the baryonic core:
      – its mass is around half of the proton’s mass
      – all baryons have the same core (different baryons have different 3 valence quarks)
      – magnetic charge is +3. Electric charge is 0.
      – there are inner closed quark shells
      – the inner quark shells contain the same number of u,d quarks. the number of other quarks is very small or zero.

      • U and D quarks do not have the same electric charge. If – as you’ve stated above – “The inner quark shells contain the same number of u,d quarks”, shouldn’t the inner core have a non-zero electric charge? (2)(2/3) + (2)(-1/3) = 2/3. The difference will only become more with increasing quantities.

        A second question- is the baryon core separate from the inner quark shells? When it was discovered that the quarks contain only half of the quark mass- does this refer only to the valence quarks or to all of the quarks?

        Thanks

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