We investigate the quantum interference between the resonant process of nuclear excitation by electron capture ͑NEEC͒ followed by the radiative decay of the excited nucleus, and radiative recombination ͑RR͒. In order to derive the interference cross section, a Feshbach projection operator formalism is used. The electromagnetic field is considered by means of multipole fields. The nucleus is described by a phenomenological collective model and by making use of experimental data. The Fano profile parameters as well as the interference cross section for electric and magnetic multipole transitions in various heavy ions are presented. We discuss the experimental possibility of discerning NEEC from the RR background.In this section we derive the total cross section of the recombination process involving NEEC followed by the radiative decay of the nucleus and RR by means of a Feshbach projection operator formalism. We consider that the electron is captured into the bound state of a bare ion or an ion with a closed-shell configuration. We calculate the interference term between NEEC followed by the radiative decay of the excited nucleus and RR in the total cross section for electric and magnetic multipole transitions of the nucleus.
A. The interference between RR and NEEC in the total cross sectionThe initial state ͉⌿ i ͘ of the system describing the nucleus in its ground state, the free electron, and the vacuum state of *Electronic address:Adriana-Claudia.Gagyi-Palffy@unigiessen.de † Electronic address: Harman@mpi-hd.mpg.de PHYSICAL REVIEW A 75, 012709 ͑2007͒