Slide 11
Slide 11 text
IMAGINARY ANOMALOUS ATOMIC FORM FACTOR f′′(ω)
• APPROACHES TO CALCULATING f′′(ω): Standard Perturbation Theory,
Relativistic Perturbation Theory, Relativistic S-Matrix Theory
• RELATIVISTIC PHOTON ABSORPTION AND EMISSION OPERATORS (QFT)
Ai
=
j
¯
α · ˆ
ǫj
eiki
·rj A†
f
=
j
¯
α · ˆ
ǫj
e−ikf
·rj
Sum over j electrons, ¯
α = Dirac alpha matrix, ˆ
ǫj = photon polarisation,
k = photon wavevector, k′ = ejected electron wave vector, rj = coordinate of
j-th electron.
• RELATIVISTIC PHOTOIONISATION AMPLITUDE: HYDROGEN
A1
(k, k′) = ψc
|Ai
|ψ0
= ψc
|eik·r ¯
αj
|ψ0
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