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Search for the Electron Electric Dipole Moment

Search for the Electron Electric Dipole Moment

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Search for the Electron Electric Dipole Moment

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  1. Search for the Electron Electric Dipole Moment Experiment: D.DeMille, D. Kawall, R.Paolino, V. Prasad F. Bay, S. Bickman, P.Hamilton, Y. Jiang, Y.Gurevich Yale University L.R.Hunter (Amherst) Theory: M. Kozlov (PNPI, St. Petersburg), D. DeMille Val Prasad Yale University

  2. D S An EDM Violates Parity and Time Reversal Symmetries and may provide evidence of new physics P T look different after P reversal look different after T reversal T-violation: a window to new physics CPT theorem T-violation = CP-violation

  3. e e Feynman Diagram not renormalizable  loop diagrams

  4. Theoretical Predictions for de NAIVESUSY HsF M-H AC Align A-CP A-Un LR-S L-FC E-Un TC YaleI (projected) Yale II(projected) Berkeley SO(10) GUT StdModel 10-26 10-30 10-28 10-32 10-40 de (e·cm) Experimental limit: |de| < 1.610-27 ecm (Berkeley)

  5. B General Method to Detect an EDM  E spin Energy Shift Resolution ~____(de.Eeff)_______ (Tcoh .√(dN/dt Tmeas))-1

  6. Schiff’s theorem Cannot apply an electric field to a free electron for long times Use a neutral object (atoms, molecules) Near nucleus, v, E,  large + substantial amplitude for valence e-: r ~ a0/Z; v ~ Zc; E ~ Ze/r2; B ~ea0; (0) ~Z1/2 |<Eeff>|  Z32 (e/a02)  P

  7. Molecules enhance electric fields Atoms • Large laboratory fields ~50 kV/cm • Leakage currents=BAD!!! • Smaller enhancement factors O E Eext~10 V/cm Eint~1010 V/cm Pb Molecules • Unpaired electron=free radical • Boltzmann distribution over many rovibrational states M. G. Kozlov and D. DeMillePhys. Rev. Lett. 89, 133001 (2002)

  8. =0 =-1 =+1 =1 states coupled in 2nd order via molecular rotation (Coriolis) E ~ (Erot)2/Est ~ 10-3Erot Symmetric-antisymmmetric states split by tunneling An aside: what’s an -doublet? Non-rotating molecule has internal tensor Stark shift 

  9. Thallium vs PbO* PbO*: ΔEedm = 2.5 x 1025 Hz x de (e-cm)

  10. Excitation scheme 2+ 2- X(0)[1Σ+] 1- 1+ ~12 MHz a(1) [3 Σ+] 2+ Laser pulse λ~571 nm t~10 ns Bandwidth~1GHz~ΔνDoppler R0208Pb J’’=0→J’=1 1- ~10 GHz 0+

  11. X(v’’ = 1) a(v’ = 5) excitation ( = 571 nm) a(v’ = 5) X(v’’ = 0) detection ( = 548 nm) Integrated over ~200 s after each pulse Integrated intensity R0(J”=0J’=1-) 208Pb Tune laser here Molecular Spectra

  12. Omega Doublet ν~11.2 MHz νZeeman~300 kHz m=0 m=-1 m=1 E =0 B =0

  13. Excitation Scheme RF pulse B E

  14. Excitation Scheme RF pulse B E

  15. Excitation Scheme B E RF pulse

  16. Quantum Beats • Coherent superposition of two states decaying to the same state • Precession frequency proportional to energy difference between states • Allows for Doppler free, very precise spectroscopy (<1mHz) y x

  17. Systematics Considerations • Motional Magnetic Fields • Magnetic Noise • Leakage Currents • Multi-photon ionization • E-field gradients • Inhomogeneities in E-field • Stray B-fields and E-fields

  18. g-factor measurement To what extent is the - doublet a perfect mirror image? -doublet useful as Co-Magnetometer  Results help constrain calculation of enhancement-factor

  19. Typical Data Averaged over 0.5 s, Bz~60 mG

  20. Rabi Flopping

  21. Stark Shift = Zeeman Shift

  22. Omega Doublet ν~11.2 MHz νZeeman~300 kHz m=0 m=-1 m=1 E =0 B =0

  23. Conclusions • Many preliminary steps have been successfully demonstrated • Improvements in excitation and detection efficiencies look promising • Attacking a few remaining experimental issues before we take a first look at the data …………….