Insight into Nuclear Excitations: Using Two-Photon Electron Transitions

摘要

A new mechanism for nuclear excitations via two-photon electron transitions is proposed and studied theoretically. Detailed calculations were performed for the E1E1 1s2s ~1S_0 → 1s~2 ~1S_0 two-photon decay of heliumlike ~(225)Ac~(87+) ions and, especially, for the resonant excitation of the 3/2+ isomeric state at the energy 40.09(5) keV. The probability for such a two-photon decay via the nuclear excitation is found to be P_(NETP) = 3.5 × 10~(-9). The possibility for an experimental proof of the proposed mechanism is discussed.