1. A single trapped Ra+ Ion to measure Atomic Parity Violation
Lorenz Willmann, University of Groningen
PSI2013 Workshop Sept. 9-12, 2013
M. Nunez Portela, E.A. Dijck, A. Mohanty, O. Boell, S. Hoekstra, G. Onderwater, S. Schlesser, RGE Timmermans, H.W. Wilschut, K. Jungmann

2. Weak Interaction in Atoms
Interference of EM and Weak Interactions
Atomic theory required

3. Weak Interaction in Atoms
Interference of EM and Weak interactions
E1PNC = Kr Z3 Qw = Kr Z3 (- N + Z (1-4sin2 θW))
3% accuracy:

4. increase faster than Z3 (Bouchiat & Bouchiat, 1974)
Scaling of the APV
increase faster than Z3 (Bouchiat & Bouchiat, 1974)
Kr relativistic enhancement factor
Z3Kr
Ra+ effects
larger by:
20 (Ba+)
50 (Cs)
Ra+
Enhancement Z3
L.W. Wansbeek et al.,
Phys. Rev. A 78, (2008)
Ba+
Ca+
Sr+
Atomic Number
 5-fold improvement over Cs feasible in 1day
Relativistic coupled-cluster (CC) calculation of E1APV in Ra+
E1APV = 46.4(1.4) · iea0 (−Qw/N) (3% accuracy)
Other results:
45.9 · iea0 (−Qw/N) (R. Pal et al., Phys. Rev. A 79, (2009), Dzuba et al., Phys Rev. A 63, (2001).)

5. sin2(θW) = (1 – (MW/MZ)2) + rad. corrections + New Physics
Weinberg Angle θW
sin2(θW) = (1 – (MW/MZ)2) + rad. corrections + New Physics 5 4 3 Cs
≈ 3 % 5 2 1
Ra+
QW(p)
eD-DIS

6. Physics Beyond the SM Extra Z’ boson in SO(10) GUTs:
Additional U(1)’ gauge symmetry
Does not affect ordinary Z and W
physics
Assume no Z-Z’ mixing
Londen en Rosner (1986)
Marciano en Rosner (1990)
Altarelli et al. (1991)
Bounds on MZ’ from APV
(68% confidence level, ξ= 52°)
With current Cs result
Mz’> 1.2 TeV/c2 (Wansbeek et al.. PRA (2010))
Range for Ra+ (5-fold improvent)
> 6 TeV/c2
From High Energy Experiments
Tevatron
MZ’> 0.9 TeV/c2 Expected Range LHC
MZ’ ~4.5 TeV/c2

7. Experimental Method Differential Light shift Energy splittings
not to scale
N. Fortson, Phys. Rev. Lett. 70, (1993)

8. Towards APV in Ra+ Ra+ production Atomic wavefunctions calculations
measure
Infer weak charge
Calculated from atomic wavefunctions
Ra+ production
Atomic wavefunctions calculations
Laser spectroscopy of Ra+
E1APV measurement:
trapping and laser cooling ions
single ion detection and spectroscopy
localize ions
parity violation measurement
Thesis:
O. O Versolato
G. S. Giri
L. W. Wansbeek

9. Sources or fragmentation
Radium Isotopes
206Pb + 12C ARa + (218-A) n
206Pb beam
12C target
TRIμP separator
Thermal ionizer
ΔN <10
To RFQ (Paul trap)
Rate after TI
225Ra
Electrochemical extraction from 229Th source (ANL)
Long lived 229Th source in an oven
Other Isotopes
Online production at accelerator facilities
( flux ~ 105/s)
ISOLDE , CERN ( flux ~ 109/s)
We produced radium isotopes using AGOR cyclotron. Etc. LIFETIME OF THE ISOTOPES PRODUCED
Sources or fragmentation 9

10. Trapped Ra+ Spectroscopy
Radiofrequency Quadrupole (RFQ)
7P3/2
7P1/2
708 nm
1079 nm
6D5/2
6D3/2
468 nm
7S1/2
Level Scheme of Ra+

11. Laser Spectroscopy in Ra+ 6d2D3/2 HFS measurement
̴̴ 3,5 σ
Probe of atomic wave functions at the origin
Probe of atomic theory & size and shape of the nucleus
O. O Versolatao et. al., Phys. Lett. A375 (2011) 3130–3133
G. S. Giri et al. Phys. Rev. A 84, (R) (2011)
[10] B.K. Sahoo et al. Phys. Rev. A, 76 (2007)
B.K. Sahoo et al. Phys. Rev. A, 79, (2009)

12. Atomic wave functions at the origin Probe of S-D E2 matrix element
Ra+ measurements
Hyperfine Structure:
Atomic wave functions at the origin
Isotope Shifts:
Atomic theory & size and shape of the nucleus
We used this system in Fall 2009 to perform measurements and extract hyperfine structures, isotopes shifts and even a lower bound of the lifetime of a meta-stable state in ra+.
State lifetime:
Probe of S-D E2 matrix element
agreement with theory at % level (Safronova, Sahoo Timmermans et al.)

13. Single Ra+ experiment Ra+ Ba+ Hyperbolic Paul Trap Iso-electrical__
Hyperbolic Paul Trap
Iso-electrical
proven IBM design
large volume
RF spectroscopy
Optical shelving
Towards single Ra+ trapping
Localization of ion to fraction of wavelength
Ba+

14. Ba+ Ion Laser Cooling on strong transitions Localisation
5D3/2
5D5/2
650 nm
493 nm
6P1/2
6P3/2
708 nm
Ba+
Laser Cooling on strong transitions
Localisation
Coulomb Crystal
Single ion
EMCCD camera image
Distance between ions about 10µm

15. Ba+ Ion Shelving to 5D5/2 state Quantum jump spectroscopy Single ion
Contrast dark and bright state
Lifetime of 5D5/2 state (~35s)
In progress (takes time)
6P3/2
6P1/2
650 nm
5D5/2
5D3/2
493 nm
6S1/2
Ba+
Photon counting
Bright
Dark

16. Atomic Parity Violation
Ra+ Clock
Narrow transition, ultra stable lasers
Low sensitivity to external fields for some transitions (I=3/2)
Major systematics:
Quadrupole shift
dα/dt
relative strength
Atomic Parity Violation
Laser wavelength
27Al
< [Itano]
1 [Dzuba, Flambaum]
Z small
deep uv
199Hg
10-17 [Itano]
-400 [Dzuba, Flambaum]
atomic theory
difficult to treat
213Ra
< [Sahoo]
400 [Versolato et al.]
relativististic effects
structure calculable
diode lasers

17. Radium Ion Clock
Optical Fiber Link

18. Summary Access to weak mixing angle at low energies
Test of SM
Trapping and spectroscopy of several Ra isotopes
Hyperfine structure, isotope shifts, lifetimes
Single Ion Spectroscopy of Ba+
Towards APV and Ra+ optical clock

19. Ratio measurement
Insensitivity of Ratio of measurements of E1APV for isotopes to atomic structure.
V. A. Dzuba, V. V. Flambaum, and I. B. Khriplovich, Z. Phys. D, 1, 243 (1985)
Best case scenario:
For radium a wide range of isotopes is available

20. Measurement Cycle

21. Optical Shelving
F=2
7P3/2
F=1
7P1/2
F=1
F=0
708 nm
1079 nm
6D5/2
F=2
6D3/2
F=1
468 nm
F=1
7S1/2
F=0
Finding other resonance (62D3/2 -72P3/2 transition) by depletion of signal due to shelving in the 62D5/2 state