Search for the Electron Electric Dipole Moment Val Prasad Yale University 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

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

Feynman Diagram  ee not renormalizable  loop diagrams

Std Model: Standard Model LR-S: Left-Right Symmetric L-FC: Lepton flavor-changing M-H: Multi-Higgs TC: Technicolor AC: Accidental Cancellations HsF: Heavy sFermions A-CP: Approx. CP A-Un: Approx Universality Align: Alignment E-Un: Exact Universality M-H NAIVE SUSY AC A-CP A-Un Align HsF SO(10) GUT LR-S L-FC TC d e (e·cm) Berkeley Yale I (projected) E-Un Std Model Experimental limit: |d e | < 1.6 ecm (Berkeley) Yale II (projected) Theoretical Predictions for d e

General Method to Detect an EDM spin  E B Energy Shift Resolution ~ ____(d e.E eff )_______ (T coh.√(dN/dt T meas )) -1

Schiff’s theorem Near nucleus, v, E,  large + substantial amplitude for valence e-: r ~ a 0 /Z; v ~ Z  c; E ~ Ze/r 2 ;  B ~  ea 0 ;  (0) ~Z 1/2 | |  Z 3  2 (e/a 0 2 )  P Cannot apply an electric field to a free electron for long times Use a neutral object (atoms, molecules)

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

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

Thallium vs PbO* Atom/MoleculeThalliumPbO* GroupBerkeley Yale/ Amherst Applied field (V/cm)10 5 >15 Effective field (V/cm) 6   !! Coherence time T (ms)30.1 Count rate (1/s) 2  Figure of merit1240 Projected sensitivity (e  cm)2  / Present limit (e  cm)<1.6  ??? PbO*: ΔE edm = 2.5 x Hz x d e (e-cm)

Excitation scheme X(0)[ 1 Σ + ] a(1) [ 3 Σ+] ~10 GHz ~12 MHz Laser pulse λ~571 nm t~10 ns Bandwidth~1GHz~Δ ν Doppler R Pb J’’= 0→J’=1

Molecular Spectra R0(J”=0  J’=1 - ) 208 Pb 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 Tune laser here Integrated intensity

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

Excitation Scheme B E RF pulse

Excitation Scheme B E RF pulse

Excitation Scheme B E RF pulse

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) x y

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

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

Typical Data Averaged over 0.5 s, B z ~60 mG

Rabi Flopping

Stark Shift = Zeeman Shift

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

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 …………….