What Explains the Mass Differences Among the Three Pions?

[sudabe]

The 3 pions have different masses and we say this so because of the electro magnetic energy.if this is so then we can never measure a mass because the magnitude of the EM energy that a particle receives depends on the charged particles around it.
if you help with this dilemma i would be grateful.

 

[Meir Achuz]

The small mass differences within isotopic multiplets arise from four energies of the quarks within the particles.
1. Quark mass differences.
2. quark-quark Coulomb energies.
3. q-q magnetic moment energies.
4. QCD q-q spin-spin energies.

 

[mathman]

I was under the impression pi+ and pi- have the same mass. pi+ made from up quark and down anti-quark, while pi- consists of up anti-quark and down quark.

 

[malawi_glenn]

yes pi- and p+ have same mass, but pi0 has different mass.