Why does binding energy affect the mass of quarks, but not protons and neutrons?

[precisionart]

Why is it that the binding energy creates mass in the case of quarks but depletes mass in the case of protons and neutrons? Am i mistaken?

 

[mathman]

Please clarify your question.

creates mass in the case of quarks

and

depletes mass in the case of protons and neutrons

.

What do mean by those phrases?

 

[precisionart]

The mass of a proton is significantly greater than the mass of its constituent quarks. the mass of an atom is less than its constituent parts.

 

[Meir Achuz]

In potential models, the total mass of the constituent quarks is usually larger than the nucleon mass. Also, the q-q potential has a positive part to produce confinement, then the PE can go either way.

 

[precisionart]

so binding energy can be additive or subtractive. I am not clear on your answer (due to my own ignorance).

 

[fzero]

With gravity and electromagnetism, the interaction strength decreases as you separate two objects. It takes only a finite amount of energy to separate two objects, actually we can even say that the amount of energy is quite small compared to the mass of the objects. A bound state therefore must exist at a lower potential energy than the constituents, else it would quickly decay.

However the strong interaction is completely different, the strength of the interaction actually increases as you separate two quarks. If you attempt to separate two quarks, you will continue to add energy to the system until you actually add enough for a new quark-antiquark pair to be created. Instead of separating the system into a pair of quarks, you will have instead created two hadrons. The condition for our original configuration of quarks to be a bound state is only that the total energy of that configuration is less than the total energy of the pair of hadrons that we would create by attempting to pull a quark out the configuration. Hence there's no contradiction with the fact that the binding energy creates mass.

 

[precisionart]

Thank you Fzero. I suspected that this was the correlation.

Do galaxies exhibit a binding energy at all, whereby there mass is affected?

 

[physalpha]

quarks + gluons ------> particle(neutron, proton)
---no mass------------------mass
This step has not been proved yet.
Current LHC experiment is done to prove the origin of the mass.
Quark and gluon have no mass.