Transverse interaction contribution to the nuclear polarization effect in hydrogen-like heavy ions

We demonstrate that the transverse interaction, which has been ignored in t he previous studies, is essential to the nuclear polarization (NP) effect o n an energy level in a heavy ion. The NP correction is calculated for the h ydrogen-like U-238(92) ion with the lowest electric quadrupole excitation a nd the electric dipole giant resonance. The transverse interaction is found to remarkably reduce the NP effect for the latter nuclear excitation. It i s concluded that, in general, the effect of the transverse interaction is i mportant, unless the nucleus has a dominant excitation mode at an energy as low as hc/(r), where (r) is the electronic mean radius.