How is the mass of hadrons calculated from constituent quarks? It seems classically it should come from three parts: (p2+m2)1/2 for each constituent quark with rest mass m, plus interactions between the quarks, which would be electromagnetic Coloumb 1/R potential between any two of the three quarks, and the linear R potential between any two quarks which is responsible for confinement at strong coupling. Quantum mechanically, if you could measure the size of the hadron, and assume the quarks are confined to a box of that size, then you would only need to add the rest mass of the quarks to the particles-in-a-box energies to get the energy of the hadron, and wouldn't have to know the momentum p of each constituent quark or the coefficient of the string potential R. Is this right? I seem to recall that the u and d quarks are taken to have almost zero rest mass. So is all the energy of hadrons made from those quarks due to E&M and confinement? What about hadrons involving heavier quarks?