Second-order quasiparticle electron energies

Here 7, is the total angular moment of the initial target state indices and are the incident and discrete state energies, respectively to the incident and captured muons. Further it is convenient to use the second quantization representation. In particular, the initial state of the system atom plus free muon can be written as a l final state is that of an atom with the discrete state electron, removed electron and captured muon in further 7 > represents one-particle (IQP) state, and F > represents the three-quasiparticle (3QP) state. The imaginary (scattering) part of the energy shift ImAE in the atomic PT second order (fourth order of the QED PT) is as follows [27,31] ... 

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