Answerer

Hi guys, I know quarks attract each other and combined only with those of different 'colours' to get a colourless mixture. And as a result of Pauli exclusion principle, quarks are forbidden to combine with those of a same 'colour'. So now my question is how do quarks of a boson react to the other quarks(of the same 'colour') of a nearby boson? Replusion or simply 'ignored'?

Feather

Well, if the quarks comprising a boson come close enough (i.e. within the range of the color force) then the exclusion principle would indeed apply. I'm not that far into my studies, though, so I could be wrong here.

In any case, my understanding is that in order for such a scenario to apply, two such bosons would have to have "collided" (and then some), because quarks are pretty much confined to the structures they are part of via the color force. I recall a seminar where a particle physicist (experimental) was describing his group's attempts to isolate quarks, and every time they "popped" one out of a less elementary particle some wierd exchange happened, the quark "popped" back in practically instantaneously and energy was released (in the form of light and other particles). But I could be recalling that badly, too.


I'm more interested in cosmology and chaos theory anyway. So I'll just shut up now.

Undercurrent

I think you mean "baryon" rather than "boson". Bosons aren't componsed of quarks.

My expectation, (and this should be overuled by any QCD major here,) is that if two different baryons (say, a proton and a neutron) are near to each other, like in a deuterium nucleus, the quarks within the proton interact with each other much more strongly than they do with the quarks of the neutron, so, to a first approximation, we can say we are dealing with two colourless particles and can ignore the great bulk of the strong interaction between them.

The second approximation would have to deal with the fact we're not dealing with a single colourless point particle, but rather three closely-coupled coloured particles. There would probably be a slight tendency for the quarks to re-orient themselves to lower the energy of interaction between themselves and the quarks in the other particle, like a spin glass. But since that tendency would be dwarfed by the intra-baryon interaction energy, the quarks wouldn't move very far out of a lowest intra-baryon energy state.

And there's something about pion exchange here, I'm sure, but I'll leave that to someone who knows what he's talking about.

Answerer

Undercurrent, thanks for correcting my mistake. Anyway, my main problem remains, besides attracting the other quarks with different 'colours' from them, do quarks actually repel those quarks that are of the same 'colour' as they are or do they simply ignore those same 'colour' quarks?

Boro Nut

Are you kidding? I can't stand them.

Boro Nut

Darwin's Beagle

As someone said quarks make up baryons. They are also charged. Quarks have either a + or - 2/3 charge or a + or - 1/3 charge. Thus, a proton which has a charge of +1 is composed of 3 quarks, two with a +2/3 charge and one with a -1/3 charge. The two quarks with a +2/3 charge should repel each other due to the ELECTROMAGNETIC FORCE. However, quarks also "feel" the STRONG NUCLEAR FORCE which acts only locally (since the gluons that mediate that force are of high mass) and is stronger than the electromagnetic force. The strong nuclear force is only attractive. Thus, the net force "felt" by quarks is attractive.

Regards,

Darwin's Beagle

Answerer

Obviously not, especially when I have other better things to joke with. After some help from my friends and some web surfing on my own, I discovered that quarks do repel each other through strong nuclear force(as long as the total addition of the colours between the quarks is not white), here is some of the web containing the evidence:

http://teachers.web.cern.ch/teachers...20vertices.htm


http://home.att.net/~lfretzin/notesP10.htm


http://www.geocities.com/tibpuzzle/Quarks.html