Autoionizing transitions

A elassieal expression for the eross seetion for eollisional de-excitation of He(2 P) is also derived from the formula by Eq. (16). However, the autoionization widths r R) for Penning ionization by resonant atoms are not identical to the empirical form of Eq. (18) for electron exchange. Instead, a direct transition due to a dipole-dipole interaction is proposed to govern this Penning ionization [126,139,140,143], that is,... 

A one-level system e) that can exchange its population with the bath states [/) represents the case of autoionization or photoionization. However, the above Hamiltonian describes also a qubit, which can undergo transitions between the excited and ground states e) and g), respectively, due to its off-diagonal coupling to the bath. The bath may consist of quantum oscillators (modes) or two-level systems (spins) with different eigenfrequencies. Typical examples are spontaneous emission into photon or phonon continua. In the RWA, which is alleviated in Section 4.4, the present formalism applies to a relaxing qubit, under the substitutions... 

A Fano profile was originally derived to interpret an asymmetrical spectral feature of autoionizing atoms [12], but it can also be identified in the electric spectrum of some simple molecules, which indirectly or directly dissociate. It has been known that a transition from an electronic ground state to a resonance state in the excited-state PES, formed through a mixing between zero-... 

For the optical transition from the bound 6snt state to the autoionizing 6pn state the optical cross section is given by the Lorentzian form... 

Energy Spectrum of Many-electron Atom. Radiative and Autoionizing Transitions (Initial Formulas)... 

Radiative and autoionizing electronic transitions. Generalized expressions for electric multipole (Ek) transition operators... 

Excited states may decay also in the process of autoionization, with the detachment of an excited electron and its transition to the state of a continuous spectrum (free electron). 

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