Quantum Electro-dynamic Corrections of 1s1/2 Energy Level in Hydrogen like Atoms

We have calculated the one loop QED corrections in 1s1/2 level for hydrogen like atoms for Z=1-92. The self energy (which now automatically contains the vertex correction) and the vacuum polarization corrections are calculated with finite size nucleus. The results are calculated using non relativistic and relativistic approaches. For light nuclei (Z=1-20) the two approaches give approximately the same results. For heavy nuclei (Z=20-92) the relativistic effect increases with increasing Z. The effect of finite size on the low energy part of self energy and the total energy shift is very small for light atoms and increases slowly with Z until Z=20 and begins to decrease until Z=80 and then increases for higher Z. The volume of the nucleus gives a large difference for high Z in the vacuum polarization and increases the vertex correction slowly with Z. The contribution of the shape of the density of light nuclei is very small.