All Questions
2
questions
3
votes
2
answers
161
views
How do we known that $\langle \bar{\psi}_i \psi_j\rangle=(250 MeV)^3\delta_{ij}$?
I have started to read the phenomenology of QCD in low energy regime. I understand that, from the QCD renormalization group equation, the QCD becomes nonperturbative theory when energy scale is below $...
- 31
9
votes
1
answer
739
views
Why do we have a non-zero quark vacuum condensate even though the QCD coupling goes to zero in the deep infrared?
It is well-known that QCD has a Landau pole at $\Lambda_{\rm QCD}\sim 200$ MeV, which means that the perturbative QCD coupling becomes strong at this scale. Conventionally, this is claimed to be the ...
- 1,783