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siupa

They want to stick way more than they want to pull apart. Besides having electric charge, quarks also have color charge. The first one lets them interact via electromagnetism, and since the electric charges have the same sign they repel with a certain strenght. The second one lets them interact via the strong interaction, and the configuration of their color charges results in an attractive force with a certain strenght. The intrinsic strenght of the strong interaction is, as the name suggests, stronger than the the intrinsic strenght of electromagnetism. So, the attractive force between the up quarks inside the proton is stronger than their electric repulsion


sandwichsupremacy

OH WAIT, So if the color charge is stronger, and since those quarks have 3 colors, the colors attract more than the electromag. Charge that should pull them apart? Technically meaning, that if quarks wouldnt have that color charge, they’d just bounce off? Am I understanding correct?


siupa

I wouldn't say that the color charge is "stronger", the color charge is what it is, as is the electric charge. The "stronger" thing is the interaction itself, the "constant" that enters in the formula for the force if you want. Anyways yes, if quarks didn't have color charge they would just bounce off and not form any proton or neutron. The up and down quarks would still attract electromagnetically since they have opposite sign electric charge, but I don't know if they would form some kind of bound state honestly


sandwichsupremacy

Yeah yeah I worded that incorrectly, it’s not “an object”. But the color charge is = to gluon exchange? What describes the needed “factors” for them to exchange certain gluons? Where does the “color” come from?


siupa

>But the color charge is = to gluon exchange? Color charge is a property of a particle, guon exchnage is a process between particles, so it's not like they're "equal". What is true is that a particle having color charge implies that it will exchange gluons with other colored particles >What describes the needed “factors” for them to exchange certain gluons? Just like electrons constantly exchange photons with other charged particles, quarks constantly exchange gluons with other colored particles. The only difference is that the photon has no electric charge, while gluons have color charge. So, electrons don't change charge after exchanging photons, but quarks do change color after exchanging gluons. The factor needed for quarks to exchange gluons therefore is just having the right color to couple with the apporpriate coloured gluon, and it happens all the time inside hadrons (quark bound states like the proton). >Where does the “color” come from? Just like electrons "just have" electric charge as an intrinsic property, quarks "just have" color charge as an intrinsic property. We don't know where it comes from, it just exists. Maybe in the future we will know if they come from something more fundamental, like if all interactions actually come from a single unified interaction at high energies that got "splintered" into the different interactions that we see today after the universe cooled down, but for now this is the most fundamental we can get


sandwichsupremacy

Yes, the first one is what I meant. But yooo, I’m actually understanding this. Is there some factor that influences quarks to change into a certain color after gluon exchange?


siupa

It depends on what the color of the gluon the quark interacted with is. Color is conserved in interactions so if a red quark absorbs a green/anti-red gluon it becomes a green quark


sandwichsupremacy

OHHH


AxolotlsAreDangerous

They’re repelled due to electromagnetic forces (which I assume is what you’re referring to), but attracted due to the strong force. The strong force is stronger.


sandwichsupremacy

Yess yes, so is the color force that’s stronger?


debunk_this_12

If by color force u mean strong force, yes at a small enough distance the strong force dominates the em forces.


sandwichsupremacy

Oh yeah I meant strong force lol. Though I’m still having a hard time understanding how do quarks “change” once the interaction with the gluon happens. If gluons also have “color”, means that 2 interactions must’ve created something else/changed “color”. Or I’m just misunderstanding everything atp


sandwichsupremacy

Also, how do gluons “interact” with eachother?


debunk_this_12

Gluons are force carrying (gauge) bosons, think of this as they are the strong force. The strong force, em, and the weak force are all mitigated by these bosons. Em is mitigated by photons(U(1)), the weak force is mitigated by the vector bosons, w and z bosons(SU(2)), and gluons form an octet (SU(3)). Think of this octet as a combination of color charges g=(red, anti-blue), (anti-red, blue), (blue-anti green), … gluons them selves interact with each other by exchanging these color charges, theoretically gluons can form a “glue ball” where by gluons interact with eachother constantly causing a bound energy and a massive object. Now think of quarks, quarks can have only one color charge. Imagine a quark emits a gluon, the initial state of the quark is green and it becomes red. The gluon it emits will have a color of green-antired. Edit: Also note color charge is conserved meaning if u have some net color charge of green in the system, the gluon it emits must contain green-anticolor for the quark to have a charge of color.


siupa

Just a small correction that is probably beyond the scope of this discussion, but the massive vector bosons that mediate the weak interaction W,Z do not form a triplet of SU(2). They exist in the broken phase after electroweak symmetry breaking, hence the original SU(2) symmetry under which the massless (W1, W2, W3) transformed as a triplet is lost. The W,Z are a linear combination of these guys (and of the B boson of the broken U(1) hypercharge)


debunk_this_12

U r absolutely correct that was my laziness and mistake


sandwichsupremacy

Ooooh ok right makes sense. So a gluon is just the energy that a colored quark releases for the “reaction” to happen..?


WheresMyElephant

It looks like you're getting good answers. I just wanted to add, it's okay if it doesn't all make 100% sense. It's way too complicated to understand in 48 hours. Most physics students don't even start studying quantum mechanics until 2 or 3 years into college, and this is quantum field theory which is more like year 6! I want to talk about the complications for a moment because it's really neat, but don't let it stress you out; please just ignore this post if it's not what you need for your studies right now. The inside of a proton or neutron is tremendously complicated and we're still studying what goes on in there. It's a lot more than three quarks tossing gluons back and forth between them. One of those gluons might turn into a strange and anti-strange quark, and those might send off their own gluons before annihilating each other and turning into a gluon again. (Or a gluon might simply become two gluons, with no quarks in between.) And you can basically end up with an infinite number of gluons as a result. These are called "virtual particles." (Some will say this is a misleading way to describe Feynman diagrams, which is kind of true, but I don't really know a better way at this level.) Technically, the same sort of thing also happens with the weak force and the EM force. A photon can't turn into two photons directly but it can turn into a virtual electron+positron which emit their own virtual photons and so forth. But for those forces, it doesn't happen *as much*. When we're doing the calculations for those forces, we can usually just ignore it. Or if we want to be very precise, we can account for the simplest possibilities where there are only a few virtual particles. The strong force is so strong that this technique doesn't work in most cases. You actually have to consider an infinite spiral of virtual particles, or your prediction about what happens inside a proton will just be *completely* wrong. And in fact, the mathematical tools to solve this problem are still being developed! Anyway, you might enjoy [this animation](https://youtu.be/G-9I0buDi4s&t=14m) of the inside of a proton even if the explanation seems hopelessly vague.


slashdave

The force that sticks gluons to each other is stronger than the repulsive electromagnetic force. It just isn't any more complicated than that.


midnight_mechanic

So here's an example to demonstrate the strength of the strong force. Something like 85% of the mass of an atom is the gluons which gold the quarks together to form protons and hold the nucleus together Put another way, the vast majority of the weight of everything is the binding force holding the nucleus together. The strong force is very strong.