The quark mass is somewhat misleading: It's not the mass of a "free" quark, that doesn't exist, because of confinement. The incredible strong nuclear force actu

The quark mass is somewhat misleading: It's not the mass of a "free" quark, that doesn't exist, because of confinement. The incredible strong nuclear force actually /lowers/ the mass of the proton compared to the sum of the unbound constituents, from "infinity" to some finite value. Strange, I know, but similar to what happens with the hydrogen atom: In the ground state, it's 13.6 eV less massive than the sum of the mass of proton and electron.