Isotope shift, non-linearity of King plot and search for

Isotope shift,
non-linearity of King plot
and search for nuclear island of stability
V. V. Flambaum, A. J. Geddes and A. V. Viatkina
18th May 2017
FFK-2017, Warsaw, Poland
Isotope shift
𝜈
𝜈 + Ξ”πœˆ
βˆ†πœˆ = 𝐼𝑆 = 𝑀𝑆 + 𝐹𝑆
Normal mass shift (NMS)
center of mass change
(finite nuclear mass effect)
Field shift
nuclear electric
charge distribution
Specific mass shift (SMS)
electron correlation
R
R+Ξ΄R
Field shift
single-electron approximation
Point-like nucleus
Uniformly charged spherical nucleus
R
Potential
r
V(r)
R
r
V(r)
𝑍𝑒 2
𝑉=
π‘Ÿ
𝑍𝑒 2 3
π‘Ÿ2
𝑉=
βˆ’
𝑅 2 2𝑅2
Field shift
single-electron approximation
Point-like nucleus
Uniformly charged spherical nucleus
R
Perturbation
r
𝛿𝐸1 = πœ“0 |𝛿𝑉|πœ“0
V(r)
R
r
V(r)
V
|πœ“0 π‘Ÿ β†’ 0 | β†’ ∞
𝛿𝑉
[1] G. Racah, Nature 129, 723 (1932).
[2] J. E. Rosenthal and G. Breit, Physical Review 41, 459 (1932).
V
|πœ“0 π‘Ÿ β†’ 0 | β†’ π‘π‘œπ‘›π‘ π‘‘
𝛿𝑉
1
12 πœ…(πœ… βˆ’ 𝛾)
2𝑍𝑅
π›Ώπœ€πœ… =
×
2
𝑧𝑖 + 1 2 πœ… + 1 2 πœ… + 3 [Ξ“ 2𝛾 + 1 ]
π‘Žπ΅
𝑍 βˆ’ nuclear charge
𝑅 βˆ’ (equivalent) nuclear radius
𝑧𝑖 βˆ’ ion charge
πœ… βˆ’ Dirac quantum number
πœ… = -1
1
-2
2
πœ… 2 βˆ’ (𝛼𝑍)2
πΌπœ…3 𝛿𝑅
𝑅𝑦 𝑅
𝛿𝑅 = 𝑅2 βˆ’ 𝑅1
πΌπœ… βˆ’ ionization potential of the electron
π‘Žπ΅ βˆ’ Bohr radius
𝑅𝑦 βˆ’ Rydberg constant
-3
…
𝑠1/2 𝑝1/2 𝑝3/2 𝑑3/2 𝑑5/2 …
𝛾=
2𝛾
Island of stability
β€’ Isotopes with (theoretically predicted)
magic neutron number N = 184 are not
produced in laboratories.
β€’ Possibility: find them in astrophysical data?
[1]
β€’ Calculate isotope shifts for N = 184 isotopes
and add them to spectra of synthesized
isotopes.
[1] V. A. Dzuba, V. V. Flambaum, and J. K. Webb,
arXiv:1703.04250 (2017)
King plot
𝐼𝑆 = 𝑀𝑆 + 𝐹𝑆
βˆ†πœˆ1,𝐴𝐴′ = 𝐾1 πœ‡π΄π΄β€² + 𝐹1 𝛿
mass shift
πœ‡
2𝛾1
π‘Ÿπ΄π΄β€²
+ 𝐺1 𝛿
2𝛾2
π‘Ÿπ΄π΄β€²
×
field shift
1
πœ‡π΄π΄β€²
2𝛾
2𝛾
×
𝑛2,𝐴𝐴′ = 𝐾2 + 𝐹2 π‘₯𝐴𝐴′ + 𝐺2 𝑦𝐴𝐴′
[1] King, W. H. (1963)
1
1
=
βˆ’
π‘šπ΄ π‘šπ΄β€²
𝛾1 =
πœ…1 2 βˆ’ (𝛼𝑍)2
πœ…1 = βˆ’1, 1
𝛾2 =
𝑛1,𝐴𝐴′ = 𝐾1 + 𝐹1 π‘₯𝐴𝐴′ + 𝐺1 𝑦𝐴𝐴′
βˆ†πœˆ2,𝐴𝐴′ = 𝐾2 πœ‡π΄π΄β€² + 𝐹2 𝛿 π‘Ÿπ΄π΄β€²1 + 𝐺2 𝛿 π‘Ÿπ΄π΄β€²2
𝐴𝐴′
πœ…2 2 βˆ’ (𝛼𝑍)2
πœ…2 = βˆ’2, 2, βˆ’3, 3, …
1
πœ‡π΄π΄β€²
𝑛1 vs. 𝑛2 plot
for 𝐴, 𝐴′ = 𝐴1 , 𝐴2 , 𝐴3 , …
is called King plot
King plot non-linearity
𝑛2
𝑐 = 𝐴𝐴3
β€’ Sources of nonlinearities from
higher-order contributions
𝑐
𝑛2,𝐴𝐴2
𝑛2,𝐴𝐴1
β€’ New Physics ?
Long-range force with couplings not
proportional to electric charge
should contribute to King plot
non-linearity. [1]
𝑏 = 𝐴𝐴2
π‘Ž = 𝐴𝐴1
𝑛1,𝐴𝐴1
𝑛1,𝐴𝐴2
𝑛1
[1] J. C. Berengut, D. Budker, C. Delaunay, V. V.
Flambaum et al. β€œProbing new light force-mediators by
isotope shift spectroscopy”, arXiv: 1704.05068
12
2𝑍𝑅
11
12πœ…(πœ…
πœ…(πœ…βˆ’βˆ’π›Ύ)
𝛾)
2𝑍
π›Ώπœ€πœ…πœ… =
=
×
βˆ†πœ€
×
2
2
+112𝛾2 πœ…
1 12 πœ…
3 3[Ξ“[Ξ“2𝛾2𝛾
++
1 1] ]
π‘Žπ‘π‘Žπ‘
𝑧𝑧𝑖𝑖 +
2 πœ…+ +
2 πœ…+ +
ion charge
-1
1
-2
2
-3
…
𝑠1/2 𝑝1/2 𝑝3/2 𝑑3/2 𝑑5/2 …
𝛾=
πœ… 2 βˆ’ (𝛼𝑍)2
πΌπΌπœ…3πœ…3 𝛿𝑅2𝛾
𝑅
𝑅𝑦
𝑅𝑦 𝑅
non-linearities
𝑍 βˆ’ nuclear charge
𝑅 βˆ’ (equivalent) nuclear radius
𝑧𝑖 βˆ’
πœ…=
2𝛾
2𝛾
πΌπœ… βˆ’ ionization potential of the electron
π‘Žπ‘ βˆ’ Bohr radius
𝑅𝑦 βˆ’ Rydberg constant
12
2𝑍𝑅
11
12πœ…(πœ…
πœ…(πœ…βˆ’βˆ’π›Ύ)
𝛾)
2𝑍
π›Ώπœ€πœ…πœ… =
=
×
βˆ†πœ€
×
2
2
+112𝛾2 πœ…
1 12 πœ…
3 3[Ξ“[Ξ“2𝛾2𝛾
++
1 1] ]
π‘Žπ‘π‘Žπ‘
𝑧𝑧𝑖𝑖 +
2 πœ…+ +
2 πœ…+ +
non-linearities
𝑍 βˆ’ nuclear
charge
Liquid drop
model
π‘Ÿ0 𝐴1/3 , π‘Ÿ0 =1.15
fmradius
π‘…π‘…βˆ’=(equivalent)
nuclear
𝑧R𝑖 βˆ’
πœ…=
ion charge
-1
1
-2
2
-3
…
𝑠1/2 𝑝1/2 𝑝3/2 𝑑3/2 𝑑5/2 …
𝛾=
πœ… 2 βˆ’ (𝛼𝑍)2
A
[1] Angeli, I., and K. P. Marinova. Atomic Data and
Nuclear Data Tables 99.1 (2013): 69-95.
[2] Fricke, G., Heilig, K. "Nuclear charge radii" (2004).
2𝛾
2𝛾
πΌπΌπœ…3πœ…3 𝛿𝑅2𝛾
𝑅
𝑅𝑦
𝑅𝑦 𝑅
𝑅 from experiment [1,2]
πΌπœ… βˆ’ ionization potential of the electron
π‘Žπ‘ βˆ’ Bohr radius
𝑅𝑦 βˆ’ Rydberg constant
1
12 πœ…(πœ… βˆ’ 𝛾)
2𝑍
βˆ†πœ€πœ… =
×
2
𝑧𝑖 + 1 2𝛾 2 πœ… + 1 2 πœ… + 3 [Ξ“ 2𝛾 + 1 ]
π‘Žπ‘
Liquid drop model
𝑅 = π‘Ÿ0 𝐴1/3 , π‘Ÿ0 =1.15 fm
non-linearities
2𝛾
𝑅 from experiment
πΌπœ…3 2𝛾
𝑅
𝑅𝑦
Summary
β€’ Simple analytical formula for field shift derived.
β€’ Found estimated values for isotope shift in metastable super-heavy
nuclei.
β€’ Estimated non-linearity of King plot is small, but for Yb+ and Hg+
above 1 Hz.
Backup slides
Element
Transition
IS, experiment (MHz)
IS, theory (MHz)
Ca (A=46-48)
3p6 4s2 – 3p6 4s 4p
-25.3 ± 1.0
-31
Yb (A=174-176)
4f14 6s2 – 4f14 6s 6p
993 ± 250
1217
Hg (A=202-204)
5d10 6s2 – 6d10 6s 6p
5238 ± 11
4939
CI+MBPT
No (A=259-286)
7s2 - 7s 7p
-7.2 cm^-1
[1] Fricke, G., Heilig, K. "Nuclear charge radii" (2004).
[2] V. A. Dzuba, V. V. Flambaum, and J. K. Webb, arXiv:1703.04250 (2017)
-9.2 cm^-1
Backup slides
𝑅2
5 2
= π‘Ÿ
3