Quark Masses

Quark masses are labeled "approximate mass". It is very difficult to determine its mass or to even define what is meant by quark mass, because a quark cannot be isolated.

This is especially true for the lightest generation (u and d), since most of the mass of their composites (such as protons and neutrons) does not come from quark masses, but from the confinement energy.

Hadron Masses Quark Chart Mesons Quarks