Second order hyperfine splitting with Blinder type contact operator : Finite nucleus models

Abstract

Taking the nucleus as an extended magnetic dipole the hyperfine interaction operators derived from the Dirac hamiltonian using the partitioning technique are written down. The second order hyperfine splitting in the ground state of the hydrogen atom is calculated from the contact operator for three different finite nucleus models. The results turn out to be strongly model dependent. The best (and physically reasonable) result is obtained for a nonsingular magnetic form factor. Singular form factors fail to yield physically acceptable results.