Hi everyone,
I have a question about the ##q_{1}\bar{q_{2}}## to vacuum :
$$ \langle 0 |\bar{q_{2}}\gamma_{\mu}\gamma_{5}q_{1}| q_{1}\bar{q_{2}}\rangle$$
That is the first time I try to solve the question like this.
How do we calculate the matrix about this question ?
Thank you so much!