finite size effect, and ∼0.07 keV due to the electron screening effect, provided by
the 2[He], 4[Be], 10[Ne] electron shells [79].
To conclude, let us underline that the key factors for the physically reasonable
agreement between experimental and theoretical data on the multi-electron pionic
Fig. 3 The fragments of the
X-ray spectra of the
181
Ta and
positions of the hyperfine
structure components (5g-4f
transition; experimental data
from [13])
Table 9 Theoretical and experimental data for the 4f level shift (keV) provided by the strong
pion-nuclear interaction for a number of pionic atoms (see text)
ε 4f , Γ 4f
Exp
H-like
Func.
Tau 1
ξ = 0
Tau 2
ξ = 1
Ba ξ = 1 Sek ξ = 1 Laat ξ = 1 Srg-Sha
ξ = 1
Ou r
ξ = 1
165
Ho: ε
0.29 ± 0.01 0.21
0.25
0.27
0.24
0.26
0.24
0.21
0.26
0.29
0.29
169
Tm: ε –
–
–
–
–
–
–
0.38
0.38
173
Yb: ε
–
–
–
–
–
–
–
0.44
0.44
175
Lu: ε
0.51 ± 0.04 0.36
0.43
0.42
0.41
0.36
0.46
0.50
0.50
181
Ta: ε
0.56 ± 0.04 0.47
0.57
0.54
0.53
0.47
0.60
0.55
0.55
197
Au: ε
1.25 ± 0.07 –
1.21
1.14
1.12
0.98
1.25
1.24
1.24
208
Pb: ε
1.68 ± 0.04 –
1.76
1.62
1.58
1.39
1.68
1.65
1.65
209
Bi: ε
1.78 ± 0.06 –
1.94
1.80
1.78
1.57
1.83
1.77
1.77
86
O. Yu. Khetselius et al.