# QCD quark mass parameters

I'm a little confused regarding all those different mass parameters in QCD. I'd like to be able to distinguish them and know when to use which mass.

• Running mass (dependent on energy scale?)

• Current mass

• Constitutent mass $\sim m_p/3$

• Mass function $m(p^2)$

Places where the quark mass can appear

• In the Lagrangian

• before renormalization

• after renormalization

• In the propagator