Probing New Intra-Atomic Force with Isotope Shifts: A Neat Thing to Do

We discuss a new method to search for a new very weakly interacting light boson with extremely precise atomic spectroscopy, namely, the atomic clock. The contribution of the new physics may appear as the violation of a linear relation of the isotope shift. We evaluated this effect with some simple assumptions. Since the results still have disagreements with works by the other group, we briefly mention some points which should be improved in the future.