Finite-nuclear-size effect on the Lamb shift of s_1/2, p_1/2, and p_3/2 atomic states

We consider one-loop self-energy and vacuum polarization radiative corrections to the shift of atomic energy level due to finite nuclear size. Analytic expressions for vacuum polarization corrections are derived. For the self-energy of p_1/2 and p_3/2 states in addition to already known terms we derive next-to-leading nonlogarithmic Zα terms. Together with contributions obtained earlier the terms derived in the present work give explicit analytic expressions for s_1/2 and p_1/2 corrections which agree with results of previous numerical calculations up to Z=100 (Z is the nuclear charge number). We also show that the finite-nuclear-size radiative correction for a p_3/2 state is not small compared to the similar correction for a p_1/2 state at least for small Z.