Electric Dipole Moment Searches in Nuclei, Atoms, and Molecules

Dave Kawall - RIKEN BNL Research Center and UMass

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RBRC Symposium, BNL, June 19th, 2006

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ee

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P and CP-violating processes

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Two Loop Contributions to EDMS in SUSY

( From D. Chang, W.Y. Keung, and A. Pilaftsis, Phys. Rev. Lett. 82, 900 (1999))

Rf = tan, F=two-loop function, =CP violating parameter

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Multi-Higgs

Naive SUSY

Accidental Canc. Approx-CP

Approx-Universality

Alignment

Heavy sfermions

SO(10) GUT

Left-Right Symmetric

Lepton Flavor Changing

Technicolor

10-26 10-28 10-30

Berkeley Yale I (projected)

10-32

Exact-Universality

10-40

Standard Model

Yale II (projected)

Searching for new physics with the electron EDM

• de is a powerful probe for new physics

• even a null result is interesting

Experimental limit: |de| < 1.610-27 ecm (Berkeley)

de (e·cm)

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Algorithm for finding an EDM

• Put system with unpaired spin in parallel E and B fields• Spin polarize system perpendicular to fields (superposition of spin up and down)• Torques from E and B lead to precession through angle in coherence time • Flip E wrt B, look for change in i.e. look for energy shift)

B B EB E

E=2B+2dEE=2B E=2B-2dE

Torques Parallel Torques Antiparallel

Spin Up

Spin Down

• Look for precession frequency shift dE/h

• For E=100 kV/cm, de=1 x 10-27e cm 20 nHz <--> B ~ few x 10-14 G• Only works for neutral systems

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LANL/SNS Neutron EDM Apparatus

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Eint

Pb+

O–

Eext

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Concept is simple enough …

• Picture of chamber, leads for oven, RF, electrodes, PMT, B-field coils, …

• View down lightpipe

• EDM Cell with electrodes, guard rings

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Ablation Pulse

Excitation Pulse

4HeCold Plate<4KHe Inlet

PbO

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BLIL

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Summary

No permanent EDM has been found in any system There are good reasons to expect EDMs within range of

new generation of experiments Non-zero and null results both quite interesting New experiments in different systems well underway Stay tuned - next 2-5 years will be very interesting

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Thanks for your attention!