New Regularization-Renormalization Method in Quantum Electrodynamics and Qualitative Calculation on Lamb Shift

A simple but effective method for regularization-renormalization (R-R) is proposed for handling the Feynman diagram integral (FDI) at one loop level in quantum electrodynamics (QED). The divergence is substituted by some constants to be fixed via experiments. So no counter term, no bare parameter and no arbitrary running mass scale is involved. Then the Lamb Shift in Hydrogen atom can be calculated qualitatively and simply as $\Delta E(2S_{1/2})- \Delta E(2P_{1/2})=996.7 MHz$versustheexperimentalvalue$1057.85 MHz$.