V nucl 0, R
ð
Þ= − 4 ̸ πr
ð Þ,
y 0, R
ð
Þ= 0,
ρ 0, R
ð
Þ= 4γ
3 ̸ 2
̸
ffiffi ffi
π
p
= 32 ̸ R
3
ð10Þ
Another, probably, more consistent approach is in using the relativistic
mean-field (RMF) model, which been designed as a renormalizable meson-field
theory for nuclear matter and finite nuclei [47].
2.2 Quantum Electrodynamics Effects in Pionic Atomic
Systems
Consistent and accurate account of the radiation or QED effects is of a great
importance and interest in spectroscopy of the pionic atomic systems. To take into
account the radiation (QED) corrections, namely, the important effect of the vacuum polarization one could use the procedure, which is in details described in the
Refs. [41–58, 65, 72–78]. Figure 1 illustrates Feynman diagrams, which describe a
(A4)
(A5)
Fig. 1 Feynman diagrams,
which describe a QED effect
of the vacuum polarization:
A1—the Uehling-Serber
term; A2, A3—terms of the
order [α Zα
ð ފ
n (n = 2, …);
A4—the Källen-Sabry
correction of the order
α
2 αZ
ð Þ; A5—the
Wichmann-Kroll correction
of order α Zα
ð Þ
n (n = 3)
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