On the A -Dependence of the Okamoto-Nolen-Schiffer Anomaly

A new version of the in-medium quark condensate is applied to study the Okamoto-Nolen-Schifferanomaly. The results show that the theoretical mass difference of mirror nuclei due to the neutron-proton mass difference have the right magnitude needed to explain this anomaly, and vary slowly with nuclear mass number A.