Electric dipole moments : a search for new physics

2. Electric dipole moments: a search for new physics E.A. Hinds Imperial College London Manchester, 12 Feb 2004

3. Fundamental inversions C particle antiparticle (Q -Q) P position inverted (r -r) Ttime reversed (t -t)

4. Weak interactions are not symmetric under P or C normal matter - n, m, p - readily breaks C and P symmetry. The combination CP is different normal matter respects CP symmetry to a very high degree. Time reversal T is equivalent to CP (CPT theorem) normal matter respects T symmetry to a very high degree. Symmetries

5. Electric dipole moment (EDM) breaks P and T symmetry P spin - + + (P no big deal) elementary particle - edm + + T - - (CP big deal)

6. EDM is effectively zero in standard model but big enough to measure in non-standard models direct test of physics beyond the standard model EDM violates T symmetry Deeply connected to CP violation and the matter-antimatter asymmetry of the universe Two motivations to measure EDMs

7. A bit of history neutron: Electro- 10-20 10-20 magnetic electron: 10-22 10-22 10-24 10-24 Experimental Limit on d (e.cm) 10-26 Multi SUSY Higgs f ~ 1 10-28 f ~ a/p Left-Right 10-30 10-30 1960 1970 1980 1990 2000 10-32 10-34 Standard Model 10-36 10-38

8. CP from particles to atoms (main connections) atom/molecule level nuclear level nucleon level electron/quark level field theory CP model de thallium Higgs SUSY Left/Right dq dcq neutron Schiff moment NNNN mercury Strong CP qGG ~

9. The Mercury EDM experiment University of Washington, Seattle M.V. Romalis, W.C. Griffith, J.P. Jacobs, E.N. Fortson B + dE ± E - dE Nuclear spin polarised 199Hg vapor in a double cell hw = mB w± measured optically

10. GSI992 Difference of precession frequencies gives 199Hg EDM 199 Hg EDM (10-27 e.cm) E = 9 kV/cm B = 1.5 mTstable to 0.4 pT Tcoherence~ 100s Hg edm result: Phys. Rev. Lett. 86,2505 (2001) |dHg|<2.110-28e cm

11. The Neutron EDM Rutherford-Appleton Laboratory D Wark, P Iaydjiev, S Ivanov, S Balashov, M. Tucker Sussex University PG Harris, JM Pendlebury, D Shiers, M van der Grinten, K Zuber, K Green, m Hardiman, P Smith, J Grozier, J Karamath ILL OXFORD KURE P Geltenbort H. Kraus N Jelley H Yoshiki • Ultracold neutrons in a bottle precess at frequency (mnB  dnE)/ • Reverse E to measure dn

12. GSI992 E = 4.5 kV/cm B = 1mT Tcoherence~ 130s Hg co-magnetometer (B is measured to 1 pT rms) Neutron edm result: Phys. Rev. Lett. 82,904 (1999) |dn|< 6.310-26e cm

13. Neutron: longer range plans New moderators usingliquid helium orsolid deuterium • Helium (ILL, LANL) Inside the helium Higher neutron density Higher E field • Deuterium (PSI, TU-Munich) Outside the deuterium Higher neutron density Bigger volume (fast moderation) Aiming at 3 10-28 e.cm over next decade

14. Implications of n and Hg for the theta parameter Baluni Crewther Pospelov induces neutron EDM CP strong interaction g p  × n n p gs2 q 32p2 induces mercury Schiff moment Henley & Haxton Pospelov × N Something (Peccei-Quinn?) makes q very small! p ~ GG N/ dn10-16 q  q <610-10  dHg 1 10-18 q  q <210-10

15. g g squark squark q q q q gaugino dqq (Fmnsmnig5 ) q gaugino 1 2 quark color dipole moments quark electric dipole moments c dqq (gsGmnsmnig5 ) q 1 2 scale of SUSY breaking naturally ~200 GeV CP phase from soft breaking naturally O(1) c dq, dq ~ (loop factor) sinCP c du,d, du,d ~ 31024 cm naturally n and Hg experiments give du< 2  1025 mq dd< 5  1026 ~ 100 times less! L 2 c du< 3  1026 c dd< 3  1026 Implications of Hg and n for SUSY naturally ~ a/p CP< 10-2 ?? L> 2 TeV??

16. CP from particles to atoms (main connections) atom/molecule level nuclear level nucleon level electron/quark level field theory CP model de thallium Higgs SUSY Left/Right dq dcq neutron Schiff moment NNNN mercury Strong CP  qGG

17. And now for the electron………..

18. The Thallium EDM experiment Berkeley B.C. Regan, E.D. Commins, C.J. Schmidt and D. DeMille 1st huge problem: motional interaction m  v  E analyse polarise The solution: add 2 more Tl beams going down E ± dE hw = mB B ± 2nd huge problem: stray static magnetic fields analyse polarise The solution: Add 4 Na beams for magnetometry 2 Tl atomic beams 4

19. A beautiful feature of the method amplification de E Interaction energy -deE• -585 for Tl atom containing electron electric field (Sandars)

20.  585 ÷ 585 Effective field = 72 MV/cm electron edm result: |de|< 1.6 10-27 e.cm |dTl|< 9.4 10-25 e.cm Final Tl result:PRL 88,071805 (2002) E = 123 kV/cm B = 38 mT Tcoherence = 2.4 ms Na co-magnetometer

21. No direct contamination from q problem - a pure new physics search g selectron de ~ (loop) sinCP e e ~ 5  1025 cm SUSY electron edm This time natural SUSY is too big by 300 me L 2 Theoretical consequences of electron EDM L> 4 TeV?? CP< 310-3 ??

22. The future for electron EDM experiments The Imperial experiment uses ytterbium fluoride molecules E.A. Hinds, B.E. Sauer, J.J. Hudson, P Condylis, M.R. Tarbutt, R. Darnley polarmolecules potentially 1000  more sensitive

23. First advantage of YbF: Huge effective field E Parpia Quiney Kozlov Titov 13 GV/cm (in Tl experiment hE was 72 MV/cm)

24. 2nd advantage of YbF: No coupling m v E to motional magnetic field electron spin is coupled to internuclear axis and internuclear axis is coupled to E m F- E Yb+ m E = 0 no motional systematic error

25. Forming and probing a YbF beam PMT 1500K heater YbF beam Mo crucible mirror Yb and AlF3 mixture probe laser

26. The A-X 0-0 band 13 1 3 5 7 9 11 15 17 19 13 1 3 5 7 9 11 15 17 19 174P(8) 174P(8) 174P(9) 174P(9) 174Q(1) 174Q(1) 174Q(0) 174Q(0) 4 5 6 174Q(0) 172P(8) 176P(9) GHz 0.2 0.4 0.6 0.8 4 5 6 bandhead at 552.1 nm GHz GHz

27. +dehE | -1  | +1  -dehE 170 MHz | 0  The lowest two levels of YbF in an electric field E X2S+ (N = 0,v = 0) F=1 F=0 Goal: to measure the splitting 2dehE

28. | +1 | -1  0 | 0  E B |+1 0 ? Pump A-X Q(0) F=1 | -1 Split Recombine Probe 170 MHz p pulse 170 MHz p pulse A-X Q(0) F=0 Phase difference = 2 (mBB+dehE)T/h Interferometer to measure 2dehE

29. The Sussex molecular beam detect PMT recombine B and E beam split pump oven 1.5 m

30. Part of the optical setup

31. The interferometer fringe Phase difference = 2(mBB+dehE)T/h Interference signal (kpps) Magnetic field B (nT)

32. E -E df = 4dehET/h - 4dehET/h Detector count rate -B0 B0 Applied magnetic field Measuring the edm

33. Effective field = 13 GV/cm background 150kHz fringe height 1.5 kHz Systematic error eliminated…. coherence time 1.5 ms de(24 hrs data) < 3 10-26 e cm First YbF result:PRL 89,023003 (2002) E = 8 kV/cm B = 6 nT Tcoherence~1 ms Limited by counting statistics

34. Supersonic YbF beam delay generator Labview control and DAQ YAG laser 1064 or 532 nm 20 mJ in 10 ns scan PMT 10 bar Ar dye laser 550 nm solenoid valve target skimmer

35. 1500K thermal source 10K supersonic source 174 Q(0) 172 P(8) 174 Q(0) 172 P(8) 176 P(9) 200 200 400 400 600 600 0 0 Laser offset frequency (MHz) Laser offset frequency (MHz) 176 P(9) 3105 useful molecules per second 3107 useful molecules per second

36. trap t ~ 1s E B supersonic source decelerator recombine probe pump split interferometer Possible experiment with trapped molecules

37. 2002 result cold YbF beam trapped molecules background 150kHz 640kHz 40kHz fringe height 1.5 kHz 160 kHz 10 kHz coherence time 1.5 ms 1 ms 1 s de in 1 day 3 10-26 e cm 6 10-28 e cm 3 10-30 e cm long time = narrow fringes Projections for the future

38. neutron: d e.cm d(muon) 7×10-19 Electro- 10-20 magnetic electron: 10-22 d(proton) 6×10-23 YbF expt 10-24 d(neutron)  6×10-26 Multi SUSY Higgs d(electron) 1.6×10-27 f ~ 1 10-28 f ~ a/p Left-Right 10-29 cold molecules 1960 1970 1980 1990 2010 2020 2030 2000 Current status of EDMs

39. Conclusion EDM measurements (especially cold molecules) have great potential to elucidate • particle physics beyond the standard model • CP violation • matter/antimatter asymmetry of the universe some of the most fundamental issues in physics