The strong force

[abskebabs]

Hi every1, I've just been revising using my physics textbook(which is rubbish btw) and it mentions that the strong force actually gets stronger as the distance between 2 quarks increases(it uses the analogy of a rubber band).This is exactly opposite to both the gravitational force and electromagnetic force. If this is true, I'm curious about what forumulas govern the strength of this force or interaction also; is it proportional to r squared(r being distance between the 2 particles)? Also does anyone know why it gets stronger as the distance between 2 quarks increases?

[swansont]

It's called asymptotic freedom and IIRC has to do with the color charge of the gluons. more basic stuff here, and the wiki entry discusses the antiscreening of the color charge when virtual quark/antiquark pairs are present.

[Meir Achuz]

It's called asymptotic freedom and IIRC has to do with the color charge of the gluons. more basic stuff here, and the wiki entry[/url'] discusses the antiscreening of the color charge when virtual quark/antiquark pairs are present.

It is not called "asymptotic freedom". (You must have read Marlon.)

The confinement of quarks is called "confinement" or "infra-red slavery".

The long distance force between quarks is now believed to have the form V=kr, leading to confinement. The property of "aysmptotic freedom" is that at small distances (<<1fm), the strong forces weakens. It is called AS because small r is related to high q^2, so the force asymptotically goes to zero as q^2-->infinity. The bag model was an early model of confinement, but now the linear form is more favored.

[swansont]

I had thought that confinement and asymptotic freedom were descriptions of the same thing, applied at different values/scales of r. (Haven't read Marlon. I picked up most of my nuclear/particle physics on the streetcorner, but thought I was on safe ground here. My mistake.)

[Severian]

Unfortunately confinement has still never been proven. Gribov claimed to have proven it but never wrote down a proof and then died.

 

It is fairly reasonable though. For small values of the coupling constant it is pretty easy to show that the strength of the force (ie. the magnitude of the coupling constant) grows as you increase the separation (this is the proof of asymptotic freedom which won the Nobel Prize recently). However, when they get far enough apart the coupling has become so large that your proof for small coupling is not longer valid.

[Alpha-137]

Dear abskebabs, swansont, Meir Achuz, Severian;

 

What is known as the strong force between the proton and neutron is really more than a single force it is a set of six fields of flux that are spun out by the six quarks at different levels. { If only I know how to up load pictures here.}

 

Well draw two spheres, and label them as the neutron and proton and show the three quarks as dots at different points / levels in side them.

 

It is the blurred orbits of the quarks that we see as the outer shells of the neutrons and protons, and it is the different levels of their orbits that give the N & P their vibrations as their fields of flux / strong forces change relatively to the quarks’ orbits.

 

Now draw an oval field of flux from each of the N quarks out and around the each of the P quarks.

 

Now draw an oval field of flux from each of the P quarks, with two encircling the quarks of the N, and one out to encircle and hold an electron in orbit.

 

Now we can see that in this atomic system we have four fields of flux holding the N & P together and that each a different level and as we start to separate them the different levels will come into play thus the forces are stronger.

 

 

In the rubber band model you would need to use more than one rubber band and each being different diameters to really see what is going on.

 

 

This is just my visual understanding of the strong forces getting stronger with distance.

 

Alpha-137:rolleyes:

[Meir Achuz]

Dear abskebabs' date=' swansont, Meir Achuz, Severian;

 

What is known as the strong force between the proton and neutron [/quote']

The strong force between nucleons is completely different than the strong force between quarks. The potential between nucleons goes to zero like

v~exp(-\mu r) for r>~1fm, with no confining potential.

[Alpha-137]

Dear Meir Achuz;

 

As I said in my posting, and if you reread it you will see that I said;

 

Now draw an oval field of flux from each of the N quarks out and around the each of the P quarks.

 

I do believe that is the force between quarks of the N & P, and it would encircling the other quarks within its’ own part of the nuclei.

 

Are? Are you saying that there is a all new set of different forces that only encircle the outer shells of the N & P that are really only the blurred orbits of the quarks that make up the N & P.

 

The electron spins out the field of flux known as the weak-electromagnetic forces and the quarks spins out the six fields of flux known as the strong force.

 

So what particle spins out the force that you say is there just to hole the N & P / nuclei together:confused:

 

Alpha-137:)

 

"Iron Rules the Universe"

[Meir Achuz]

Are you saying that there is a all new set of different forces that only encircle the outer shells of the N & P that are really only the blurred orbits of the quarks that make up the N & P.

QUOTE]

Yes. The main cause of the force between nucleons is the exchange of mesons (You may consider them them q-qbar.) between the nucleons.

That is why the N-N force is not a confining force.

[Meir Achuz]

You could go to this website for a brief discussion:

aether.lbl.gov/www/tour/ elements/stellar/strong/strong.html

I recommend avoiding wikipedia.

The best thing would be to look at a nuclear physics (or "modern physics") text.