Pion mass difference from vacuum polarization

JLQCD Collaboration, E. Shintani, H. Fukaya +5

We calculate the electromagnetic contribution to the pion mass difference, $\Delta m_{\pi }^2=m_{{\pi }^{+}}^2-m_{{\pi }^0}^2$, in the chiral limit through the $VV-AA$ type vacuum polarization using Das-…