a question about quarks

[derek w]

quote:-

Confinement,which means that the force between quarks does not diminish as they are separated.Because of this,it would take an infinite amount of energy to separate two quarks;they are forever bound into hadrons such as the proton and the neutron.

Yet an up quark and an anti-up quark,annihilate producing a gluon which then produces a top quark and an anti-top quark.

 

MY question is if it takes an infinite amount of energy to separate 2 quarks,where do you get 2 free quarks to annihilate and produce top quarks that are separated,does it take an infinite amount of energy to separate top quarks?

An infinite amount of energy would imply that separating 2 quarks would require the annihilation of the rest of the universe,leaving you with just 2 quarks.

[mathematic]

It doesn't take an infinite amount of energy to separate two quarks (in particular a quark anti-quark pair). However when trying to separate them, a lot of energy is needed. When they are finally apart, the extra energy gets converted into another anti-quark attached to the original quark and another quark attached to the original anti-quark.

[derek w]

Yes,you create 2 new quarks,because it requires less energy to do that,than to separate the original quarks.But the original quarks never get separated,so you can't say that it doesn't take an infinite amount of energy to separate the original 2 quarks,that is not proven.

 

In the big bang theory one of the first things that happens is that the quarks are bound together,seemingly forever.To have a theory and an understanding of how the universe works,the fact that the quarks are confined must be of great significance.

Edited December 28, 2011 by derek w

[MigL]

Yes, the two original quarks separate. The energy creates a new partner for each of the original two bound quarks. I'm not sure if you can tell, however, as you cannot label the quarks. You may be able to tell from conservation of momentum considerations.

[derek w]

But you still end up with quarks that are bound(confined),no individual quarks existing separate.And that is a mechanism,which I don't understand,but I feel it should be telling us something about the structure of the universe.

[mathematic]

But you still end up with quarks that are bound(confined),no individual quarks existing separate.And that is a mechanism,which I don't understand,but I feel it should be telling us something about the structure of the universe.

I am not sure what point you are trying to make. However the strong force is essential to holding atomic nuclei together. If it wasn't there, there would be no universe as we know it.

[mrs.warren]

quote:-

Confinement,which means that the force between quarks does not diminish as they are separated.Because of this,it would take an infinite amount of energy to separate two quarks;they are forever bound into hadrons such as the proton and the neutron.

Yet an up quark and an anti-up quark,annihilate producing a gluon which then produces a top quark and an anti-top quark.

 

MY question is if it takes an infinite amount of energy to separate 2 quarks,where do you get 2 free quarks to annihilate and produce top quarks that are separated,does it take an infinite amount of energy to separate top quarks?

An infinite amount of energy would imply that separating 2 quarks would require the annihilation of the rest of the universe,leaving you with just 2 quarks.

 

 

 

Try looking into Quantum Chromodynamics.... it's very enlightening information for this subject.

[derek w]

Mathematic you say " your not sure what point I am trying to make?".

 

to explain I'll give an analogy with Velcro,where the force that binds Velcro together is a collective force,each separate hook and eye is not bound by an individual strong force,but by a collective strong force.

Within the first second of the big bang all the quarks where bound together,I am trying to understand if it is a collective strong force that confines them,or is it an individual strong force?

 

And thanks mrs.Warren I will do as you suggest.

[mathematic]

Mathematic you say " your not sure what point I am trying to make?".

 

to explain I'll give an analogy with Velcro,where the force that binds Velcro together is a collective force,each separate hook and eye is not bound by an individual strong force,but by a collective strong force.

Within the first second of the big bang all the quarks where bound together,I am trying to understand if it is a collective strong force that confines them,or is it an individual strong force?

 

And thanks mrs.Warren I will do as you suggest.

Gluons exert forces on quarks. Presumably right after the big bang it was a "quark-gluon soup".

 

http://en.wikipedia.org/wiki/Quark%E2%80%93gluon_plasma

[MigL]

At that time, just after the big bang, there was also sufficient energy to keep quarks from pairing up.

As has been explaned, quark separation energy is finite and much lower than Planck scale energy

( in other words I don't know its exact value but I'm sure you could look it up, if interested ).

[derek w]

ok.I been reading the above mentioned article.The quark gluon plasma is produced at temperatures of approx 4 triillion degrees,which I assume apart from the big bang would not occur naturally any where else in the universe.Plus it also says that theoretically at some much higher temperature there would be a state of matter where there would be no difference between the plasma and the quarks.

 

question.Am I right in that the plasma is being thought of as some kind of super dense liquid(or perfect dense fluid),which condenses as it cools producing quarks and gluons.

Edited January 2, 2012 by derek w

[mathematic]

ok.I been reading the above mentioned article.The quark gluon plasma is produced at temperatures of approx 4 triillion degrees,which I assume apart from the big bang would not occur naturally any where else in the universe.Plus it also says that theoretically at some much higher temperature there would be a state of matter where there would be no difference between the plasma and the quarks.

 

question.Am I right in that the plasma is being thought of as some kind of super dense liquid(or perfect dense fluid),which condenses as it cools producing quarks and gluons.

Could you be specific as to what you are referring to? There was some discussion of a "Glasma", which is at a lower temperature than a quark-gluon plasma.

[derek w]

yeh.sorry.From that article in (contents:- 3.experimental situation) I went to the link for a summary see(2005 RHIC Assessment).and another external link the article from your suggested article was(Physics news update article on the quark-gluon liquid).

Edited January 3, 2012 by derek w

[derek w]

Brookhaven physicist Samuel Aronson said that having established the quark-gluon-liquid nature of the pre-protonic universe,RHIC expected to plumb the liquids properties,such as its heat capacity and its reaction to shock waves.The liquid is dense but seems to flow with little viscosity.It flows so freely that it approximates an ideal,or perfect,fluid,the kind governed by the standard laws of hydrodynamics.At least in its flow properties the quark liquid is therefore a classical liquid and should not be confused with a superfluid,whose flow properties(including zero viscosity),are dictated by quantum mechanics.

[derek w]

Quote from:- Brookhaven National Laboratory news.

Article title:-RHIC scientists serve up "perfect" liquid.

 

This is just a part of the article:-

That evidence comes from measurement of unexpected patterns in the trajectories taken by the thousands of particles produced in individual collisions.The measurements indicate that the primordial particles produced in the collisions tend to move collectively in response to variations of pressure across the volume formed by the colliding nuclei.Scientists refer to this phenomenon as "flow",since it is analogous to the properties of fluid motion.

However unlike ordinary liquids in which individual molecules move about randomly,the hot matter formed at RHIC seems to move in a pattern that exhibits a high decree of coordination among the particles--somewhat like a school of fish that responds as one entity while moving through a changing environment.

 

 

Question:-These articles were dated 2005,has there been any further developments,I can't find any newer information on the subject of this "perfect" liquid?

[immijimmi]

I dont know where you got the quote from, but strong force has no strength over 3 fm. Otherwise, we'd be seeing some rather large hadrons forming, granted enough quarks or energy.

[Widdekind]

http://www.bnl.gov/bnlweb/pubaf/pr/pr_display.asp?prid=05-38

 

BNL links their article to a RealPlayer animation, of the perfect fluid generated, during high-energy gold ion collisions.

 

They seem to say, that in "off center collisions", an ultra-dense, compressible, inviscid quark-gluon fluid is produced:

 

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............................

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--->

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Note that the gold nuclei are "pancaked", according to their extreme "lorentz contraction", due to their relativistic trans-luminal velocities.

 

The "fluid" seems to show "vortices", i.e. "eddy currents", in the collision-produced "stream" of QGP. Note that the (edges of the) nuclei seem to "pass through each other", whilst leaving a "stream of debris" behind the collision. I understand, that that phenomenon, like two worlds colliding, and actually generating more (molten) rock mass, than they began the encounter with, is a direct demonstration, of the conversion, of collision Kinetic Energy (KE), into a "stream" of new massive quarks (KE --> m_qc²) & gluons. Also, I understand, that that demonstrates "color confinement" of quarks, i.e. as the colliding nuclei "rip through" each other, and "rip out" each others' quarks... those "snapped" gluon bonds rapidly "regenerate" into new quark-antiquark pairs, within the "debris stream". So, I understand, that that "debris stream", trailing between the colliding nuclei after they "pass through" each other, is plausibly Electro-Magnetically & Strongly charge-neutral, i.e. only quarks - antiquarks, in bound meson-like pairs. If the debris stream was composed, of quasi-bound mesons, could that explain the "correlations" observed, in the motions, of the quarks, compared to the antiquarks, i.e. "they move the same b/c they're bound into mesons" ??

 

Perhaps the "off-center" collision, "rips out quarks", which become "color confined", into quark-antiquark mesons, rotating with non-zero angular momentum ? The animation talked about, and depicted, pairs of quark-antiquarks, co-spiraling, in vortices. So again, what if those quark-antiquarks were co-spiraling, b/c the were bound, into rotating mesons ? Naively, such seems physically feasible -- an off-center collision, imparts a rotation, into debris particles, which spin around, as if in an eddy current.

 

The researchers said, that they had expected to see a gas, of non-interacting quarks -- perhaps 4TK is not enough, to "punt quarks free & clear", but instead, their baryons only "melt" and a few quarks are "extruded out" still enmeshed in glue ??

Edited January 14, 2012 by Widdekind