Polarization of vacuum in a hydrogen-like relativistic atom: Hyperfine structure

An analysis is made of the contribution of the polarization of vacuum to th e hyperfine splitting of the ground state of a hydrogen-like atom. An expre ssion for the correction to the energy is obtained as an explicit function of the parameter Z alpha. The final expression derived in terms of generali zed hypergeometric functions and their derivatives is a function of the par ticle mass ratio in orbit and in a vacuum loop, and is therefore valid for both ordinary and muonic atoms. Various asymptotic forms are also given. (C ) MAIK "Nauka/Interperiodica".