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retupmoc

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- Thread starter retupmoc
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retupmoc

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- #2

mathman

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- #3

humanino

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More precisely : take empty space, and distrurb it with a chromomagnetic field : the energy decreases ! (Warning : don't get too much bothered, this is perturbative calculation, so nobody really expect it to work here (^_^) You might still feel a taste of what is going on) In this perspective, we imagine chromo-vacuum similar to 2D Ising model, with drops of "up" and "down" pointing spins. This should represent the structure of chromo-vacuum.

- #4

kurious

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humanino said:

People widely believe the same occurs with color field in empty space : it must be "screened" by vacuum polarization.

Are you talking about space at distances greater than 10 ^- 15 metres or just

over the range of the colour force.And what exactly is vacuum polarization in this context?

- #5

humanino

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As far as I know, color force INCREASE with distance. But the precise divergence law does not really matters, so one usually simply pick a linear growing force. Besides, the color force DISAPEAR at small distance.

Two quarks very close to each other can easily exchange their color, meaning they are for all practical purpose FREE. At large distance, they have to exchange the color in a very narrow tube between them (looking very much like a string !), which is not easy, and the force between them must be strong. This is basically the behavior of strong force.

Vacuum polarization correspond to the "drops" of vacuum with different color orientation, similar to "drops" of polarization occuring in 2D Ising model. The reason why this vacuum polarization is relevant to confinement is really technical. Let's say to sum up (and because I know I can easily go wrong on that subject !) : the fancy up-to-date lattice calculations show that confinement is due to a color Coulomb-like potential, corresponding to the instantaneous part of the 4-4 component of the gluon propagator. This potential is then screened by the vacuum polarization, and this provide an UPPER bound on the potential. This phenomenon is responsible for asymptotic freedom (vanishing of the coupling constant, or negativity of the "beta" function). To provide numbers : at 100 GeV, alpha is of order 0.1 (compare with 1/137 of QED). But the interesting part is the non-perturbative regime, at small energy or large distance. Here, screening is not effective any more, and the coupling grows infinity. Understanding what is screening should provide good clues of what happens when there is no screening anymore.

Two quarks very close to each other can easily exchange their color, meaning they are for all practical purpose FREE. At large distance, they have to exchange the color in a very narrow tube between them (looking very much like a string !), which is not easy, and the force between them must be strong. This is basically the behavior of strong force.

Vacuum polarization correspond to the "drops" of vacuum with different color orientation, similar to "drops" of polarization occuring in 2D Ising model. The reason why this vacuum polarization is relevant to confinement is really technical. Let's say to sum up (and because I know I can easily go wrong on that subject !) : the fancy up-to-date lattice calculations show that confinement is due to a color Coulomb-like potential, corresponding to the instantaneous part of the 4-4 component of the gluon propagator. This potential is then screened by the vacuum polarization, and this provide an UPPER bound on the potential. This phenomenon is responsible for asymptotic freedom (vanishing of the coupling constant, or negativity of the "beta" function). To provide numbers : at 100 GeV, alpha is of order 0.1 (compare with 1/137 of QED). But the interesting part is the non-perturbative regime, at small energy or large distance. Here, screening is not effective any more, and the coupling grows infinity. Understanding what is screening should provide good clues of what happens when there is no screening anymore.

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In case any of you missed it, keep in mind that there are a tremendous amount of similarities between the phenomena in condensed matter and that found in elementary particles. There are many who do not think it is a mere coincidence that quarks have basic charge of 1/3 and 2/3. The discovery of the fractional quantum hall effect, and consequently, fractional charge of 1/3 in 2D quantum confinment seems to imply that a fractional charge can arise out of many-body elementary excitations. Similar to the quark confiment, the fractional charge found in those condensed matter phenomena does not exist by themselves, unbounded and devoid of the many-body interactions. So this isn't just a matter of strong confinement potential.

There is a good article written by Bob Laughlin (who, incidentally was a co-Nobel winner for the fractional quantum hall effect) establishing the similarities between a condensed matter phenomena (antiferromagnetism) and the strong interaction:

http://arxiv.org/abs/cond-mat/9802180

Zz.

- #7

humanino

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- #8

Haelfix

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In the continuum limit, there is still no analytic proof of such

- #9

shakeel

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- #10

shakeel

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i am writing thesis on super symmtry .may some body help me

- #11

Olias

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ZapperZ said:

In case any of you missed it, keep in mind that there are a tremendous amount of similarities between the phenomena in condensed matter and that found in elementary particles. There are many who do not think it is a mere coincidence that quarks have basic charge of 1/3 and 2/3. The discovery of the fractional quantum hall effect, and consequently, fractional charge of 1/3 in 2D quantum confinment seems to imply that a fractional charge can arise out of many-body elementary excitations. Similar to the quark confiment, the fractional charge found in those condensed matter phenomena does not exist by themselves, unbounded and devoid of the many-body interactions. So this isn't just a matter of strong confinement potential.

There is a good article written by Bob Laughlin (who, incidentally was a co-Nobel winner for the fractional quantum hall effect) establishing the similarities between a condensed matter phenomena (antiferromagnetism) and the strong interaction:

http://arxiv.org/abs/cond-mat/9802180

Zz.

You are so right, Laughlin has done some really interesting work. What really is amazing is that the Quark Confinement is based on a potential of Electro-Magnetic-Vacuum quantities outside of Einsteinien Spacetimes. Just as the Virtual Photon eminates from a un-identified Spacetime, so does the energy needed to seperate Quarks. For every positive energy amount we throw at them in seperation, an ample amount of negative energy materials materials out of nowhere and maintains the Quark Hierarchy.

The opposite is true for Quantum Hall systems, there is a definate outpouring of Explosive Nova from deep within certain B-E-C superconductive condensed states.

A good example here is the Bose-Nova, where the confinment is broken from within the condensate, exactly the opposite of what we try to do with seperating Quarks (negative-energy infill?) there is a positive outpouring, thus Nova.

- #12

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Olias said:You are so right, Laughlin has done some really interesting work. What really is amazing is that the Quark Confinement is based on a potential of Electro-Magnetic-Vacuum quantities outside of Einsteinien Spacetimes. Just as the Virtual Photon eminates from a un-identified Spacetime, so does the energy needed to seperate Quarks. For every positive energy amount we throw at them in seperation, an ample amount of negative energy materials materials out of nowhere and maintains the Quark Hierarchy.

The opposite is true for Quantum Hall systems, there is a definate outpouring of Explosive Nova from deep within certain B-E-C superconductive condensed states.

A good example here is the Bose-Nova, where the confinment is broken from within the condensate, exactly the opposite of what we try to do with seperating Quarks (negative-energy infill?) there is a positive outpouring, thus Nova.

Although you appear to agree with me regarding Laughlin, etc., I have absolutely no idea what you have said. For example, "BEC superconductive condensed states"?! What are those? BEC is on the OPPOSITE end of the phase line from the BCS condensation. Till a few months ago, it was thought that these two are separated via a distinct phase transition. It was only the recent discovery of the fermionic condensate that there is a real possibility that there is a smooth transition or a crossover between the two extremes. It still does not make them the same thing.

Zz.

- #13

shakeel

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may some body tell me about mass hierarchy problem .why it is prefered to use supersymmetry to solve this problem. as for as i understan that it can be tackled

by fine tunning i.e by introducing -ive terms in bare mass to cancel the divergence term which coms by radiative corrections .ma i right?

- #14

shakeel

- 23

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i am writting thesis on supersymmtry may somebody help me ,may someone send me matrial on this icannot afford to by books due to poor financial conditions

- #15

Olias

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Like I said there are certain correlations, recognized (speculated) by myself some time ago, verified recently.

Of some interest:http://arxiv.org/abs/cond-mat/0405206

From some time ago, this:http://arxiv.org/abs/cond-mat/0303045

and a recent progression:http://arxiv.org/PS_cache/cond-mat/pdf/0405/0405130.pdf [Broken]

Of some interest:http://arxiv.org/abs/cond-mat/0405206

From some time ago, this:http://arxiv.org/abs/cond-mat/0303045

and a recent progression:http://arxiv.org/PS_cache/cond-mat/pdf/0405/0405130.pdf [Broken]

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- #16

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Olias said:Like I said there are certain correlations, recognized (speculated) by myself some time ago, verified recently.

Of some interest:http://arxiv.org/abs/cond-mat/0405206

From some time ago, this:http://arxiv.org/abs/cond-mat/0303045

and a recent progression:http://arxiv.org/PS_cache/cond-mat/pdf/0405/0405130.pdf [Broken]

What correlations? How do these things "verify" your "speculations"? I am EXTREMELY familiar with X.J. Zhou's et al. paper on LSCO, since I also did ARPES measurement on high-Tc superconductor. I see nothing in here remotely come close to strenghtening your idea of "BEC superconductor". Be careful to not fool yourself into interpreting things you do not understand. "Coupling to bosonic mode" has a very profound meaning in condensed matter physics. I would certainly not use a result from a still controversial area of high-Tc superconductor to extrapolate my idea into something even more speculative.

Furthermore, K. Levin at U. of Chicago has a whole series of theoretical papers on BCS to BEC crossover regime that showed how these two in fact can be COMPETING phenomena in a superconductor. So there are certainly loads of more different interpretation of this phenomena.

If you have published your speculation, please give citation from the peer-reviewed journals that it was published.

Zz.

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- #17

Olias

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ZapperZ said:What correlations? How do these things "verify" your "speculations"? I am EXTREMELY familiar with X.J. Zhou's et al. paper on LSCO, since I also did ARPES measurement on high-Tc superconductor. I see nothing in here remotely come close to strenghtening your idea of "BEC superconductor". Be careful to not fool yourself into interpreting things you do not understand. "Coupling to bosonic mode" has a very profound meaning in condensed matter physics. I would certainly not use a result from a still controversial area of high-Tc superconductor to extrapolate my idea into something even more speculative.

Furthermore, K. Levin at U. of Chicago has a whole series of theoretical papers on BCS to BEC crossover regime that showed how these two in fact can be COMPETING phenomena in a superconductor. So there are certainly loads of more different interpretation of this phenomena.

If you have published your speculation, please give citation from the peer-reviewed journals that it was published.

Zz.

Whoa

Lets get one thing straight, I have my own model based a little more than speculation, my interest has led me to a inter-phase(Tri-Coupled-State-Matter) model based on geometry (pure), more than soft-condensed states or other toy replicated 2-D theories.

This being said it is only a sideline interest of mine, and you are certainly correct in that I should not be babbling on about a very little understood area of pioneering hpysics, but forgive me if you will, but the main speculative hand-waving comes from reading a vast quantity of pre-print papers, many of the authors I admire greatly.

I am now going to butt out!

- #18

sol2

- 909

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The ideal experimental test of this new feature of QCD would be to study the flux tube of figure 1 directly by anchoring a quark and antiquark several femtometres apart and examining the flux tube between them. In such ideal circumstances, one of the characteristics of the gluonic flux tube would be the model-independent spectrum shown in figure 2. The excitation energy is p/r because the flux tube's mass is entirely due to its stored energy. There are two initially excited longest wavelength vibrations with identical energies because the motion of the flux tube is in the two symmetrical dimensions perpendicular to its length.

http://www.cerncourier.com/main/article/40/7/16

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