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Funding sources for preliminary research: National Research Council (US)

Measuring the Electron’s Electric Dipole Moment using zero-g-factor paramagnetic molecules APS March Meeting, 2006. Neil Shafer-Ray, The University of Oklahoma. Funding sources for preliminary research: National Research Council (US) NATO SfP (for field measurement.)

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Funding sources for preliminary research: National Research Council (US)

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  1. Measuring the Electron’s Electric Dipole Moment usingzero-g-factor paramagnetic moleculesAPS March Meeting, 2006 Neil Shafer-Ray, The University of Oklahoma Funding sources for preliminary research: National Research Council (US) NATO SfP (for field measurement.) OU Office of the Vice Presidentfor Research Current funding: National Science Foundation DOE EPSCoR Laboratory-StatePartnership

  2. To all, I am very sorry that I was not able to deliver this talk. My grandmother has passed away a few hours ago and I must return to the United States. Sunday, October 8, 11:30pm Neil Shafer-Ray

  3. K-zero-long decay http://www.bnl.gov/bnlweb/history/nobel/nobel_80.asp CP (time reversal) violation

  4. A completely different place to look for CP violationis in the interaction of fundamental particles with external fields.

  5. Hans G. Dehmelt ion trapping, spectroscopy of a single trapped electron. Nobel Prize 1989 Norman Ramsey Separated Oscillator Beam Resonance resonant line witdths <100Hz Nobel Prize 1989 STANDARD OF TIME II Rabi 1938 Magnetic Resonance resonant line widths <10kHz Nobel Prize 1944 MAINSTAY of MODERN CHEMISTRY Stern and Gerlach 1922 "space quantization" g=1 to 10% (assumed integral spin) Nobel Prize 1943 Gerald Gabrielse Quantum nondistructive measurement of the quantum structure of a single electron in a magnetic trap STANDARD OF MASS? The study of the magnetic moment of the electronis an integral part of some of the mostcompelling experiments of the last 100 years.

  6. An EDM proportional to spin would also give CP g = 2.0023193043617(16) Gabrielse,PRL 2006 gedm = 0.00000000000000000(5) Commins, PRL, 2004

  7. An EDM proportional to spin would also give CP (Arnowitt 2001) Super Sym. - Commins & coworkers, Tl, PRL, 2002 Std. Mod. - Hinds & coworkers, YbF, DAMOP, 2005 (Hoogeveen 1990)

  8. Outline Outline I. Introduction How was the current experimental limit on the magnitude of the e-EDM obtained? What are some of the current experiments beingcarried out to measure the e-edm What is the OU group up to?

  9. How the current limit on electron EDM is known Symmetry leads to a ±M degeneracy of any molecule or atom that is not broken by an electric field along the quantization axis. The existence of an electron electric dipole moment would break this symmetry. To search for an e-EDM we will look for DU=U+M –U-M in a strong E field. Major Difficulty: A backgroundmagnetic field mimics an EDM. Precision structurecalculations arenot necessary.

  10. The Commins Experiment with2P1/2 (F=1, M=±1) Tl For an isolated electron, For an atom or molecule in a strong electric field, for diamagnetic atoms for light atoms/molecules (Schiff's theorem.) for relativistic (heavy atoms/molecules.) We want to use heavy paramagnetic atoms or molecues.

  11. The Commins Experiment with2P1/2 (F=1, M=±1) Tl geometric factors enhancement factor

  12. LASER RADIATION E Graphical Description of the Commins e-EDM Experiment P(q,f) = probabilityof finding the system In the state M=F when quantization axis isin the direction of q,f. Tl(2P1/2 F=1), incoherent combination of |1,1>, |1,0> and |1,-1> states Tl(2P1/2 F=1), |1,1> + |1,-1>

  13. EFFECT OF MAGNETIC FIELDS ON THE DISTRIBUTION OF ANGULAR MOMENTUM B Tl(2P1/2 F=1), |1,1> + Exp[i DU t /] |1,-1>

  14. EFFECT OF MAGNETIC FIELDS ON THE DISTRIBUTION OF ANGULAR MOMENTUM B Bx A small constant field Bxalong an axis perpendicular to B has little effect.

  15. EFFECT OF MAGNETIC FIELDS ON THE DISTRIBUTION OF ANGULAR MOMENTUM B Brot A small field Bxalong an axis perpendicular to B that rotates with the distribution may have a dramatic effect.

  16. EFFECT OF A MAGNETIC FIELD ON OF ANGULAR MOMENTUM ORIENTATION B A small field Bxalong an axis perpendicular to B that rotates with the distribution may have a dramatic effect. The Ramsey beam resonance technique takes advantage of this dependenceof the Rabi rotation on the phase of the rotating field.

  17. LASER LASER w= DU/ =wRF B The Commins experiment Commins et al, PRL 88, 71805, 2002

  18. LASER B LASER w= DU/ wRF The Commins experiment Commins et al, PRL 88, 71805, 2002

  19. FLUORESCENCE (LIGHT SEEN) MISMATCH BETWEEN w and wRF Expected Ramsey resonance signal for nT = (2kT/m)1/2 / 2L = 140 Hz (m=100 amu , T=500K, and interaction length L= 1000mm)

  20. LASER LASER w= DU/ =wRF(+) E B The Commins experiment Commins et al, PRL 88, 71805, 2002

  21. LASER B E LASER w= DU/ =wRF(-) The Commins experiment Commins et al, PRL 88, 71805, 2002

  22. SHIFT SHOWN TO BE ~ 10-7 OF THE WIDTH!!! GREAT STATISTICS! E(-||)B E||B SHIFT GIVES EDM

  23. limiting systematic error q sinq≈10-6

  24. Measurement of the e-EDM using paramagnetic molecules B @ 10-27e cm (nG) split @ 10-27e cm (mHz) System (state) E-field (kV/cm) tcoherence (ms) dlimit (10-27e cm) Tl (2P1/2 F=1) 100 0.02 0.024 3 Commins 1.3 YbF (X2S,F=1) Hinds 10. 13 5 3 - 1) Effective electric field is the internal field of the molecule. 2) Idea by Saunders (Atomic Phys, 14 1975,71). 3) Calculation of shift by N.S. Mosyagin, M.G. Kozlov, A.V. Titov, (J Phys B, 31, L763)

  25. Effect of the large tensorsplit (energy dependence on |M|) q Only the projection of B on the E axiscontributes to the energy between ±M levels: v

  26. Effect of the large tensorsplit (energy dependence on |M|) Only the projection of B on the E axiscontributes to the energy between ±M levels: Dq q A much less severe problem then the vxE/c2 effect.

  27. Differences between an atomic beam and a beam of paramagnetic molecules Expected Flux Beam Speed Distribution Tl(F=1,|M|=1) 8 × 1015/str/sec (from oven) v(m/s) 400 800 0 YbF(J=1/2, F=1,|M|=1) 6 × 1010/str/sec (from supersonic expansion) v(m/s) 400 800 0 Easy to lose in statistics what one gains in intrinsic sensitivity.

  28. (Shafer- Ray) PbF (X2P1/2, F=1) - 60-100 12 500 to 107 103 to 3 B @ 10-27e cm (nG) shift @ 10-27e cm (mHz) System (state) E-field (kV/cm) tcoherence (ms) dlimit (10-27e cm) Tl (2P1/2 F=1) Commins 100 0.02 0.024 3 1.3 Hinds 30(1?) YbF (X2S,F=1) 10. 13 5 3 (Hinds) 15 Hunter 0.00016 0.00025 4 60 Cs (2P1/2 F=3) - 2x103 0.004 0.005 100? (Weiss) ? 0.004 0.005 ~103 - (Gould) ~1 volt RFion trap HfF+ (3D1) (Cornell) ~10 ~200 ~103 - PbO (a3S,F=1) - .01 2.9 1 0.1 (DeMille)

  29. Cs Atomic Fountain (Provided by Harvey Gould)

  30. The OU PbF edm experiment

  31. g-factor can be tuned to zero! g factor of PbF F=1, |MF|=1, high-field-seeking ground state: Shafer-Ray, PRA,73, 34102

  32. Schematic of PbF g=0 measurement optical polarization (create M=0 state) high-field region Raman-RF pump PbF molecular beam source probe + LIF or REMPI detection region (probe M=0 state) probe -

  33. Schematic of PbF g=0 measurement optical polarization (create M=0 state) high-field region Raman-RF pump PbF molecular beam source probe + LIF or REMPI detection region (probe M=0 state) probe -

  34. Pb +MgF2 reactor: Operational Temperature 1200K Pb +PbF2 reactor: Operational Temperature 1200K First things first: Production and detection of PbF Pb / F2 flow reactor: Operational Temperature 1200K

  35. Schematic of PbF g=0 measurement optical polarization (create M=0 state) high-field region Raman-RF pump PbF molecular beam source probe + REMPI detection region (probe M=0 state) probe -

  36. Current Apparatus for Exploring PbF Spectroscopy Nd:YAG 10ns, 10Hz tunable dye laser0.1 cm-1 resolution tunable dye laser0.1 cm-1 resolution Not an ideal detection scheme: PbF molecules stay in probe region ~5ms Time between laser shots: 100ms Duty cycle: 1/(20,000) detection chamber ionization chamber PbF Source Chamber

  37. Current Apparatus for Exploring PbF Spectroscopy detection chamber PbF+ PbF ionization chamber PbF Source Chamber

  38. Current Apparatus for Exploring PbF Spectroscopy detection chamber PbF+ PbF ionization chamber PbF Source Chamber

  39. 1+1 X12P1/2→B2S1/2 REMPI of PbF McRaven, Poopalasingam, Shafer-Ray, Chemical Physics Letters, In Progress. 5.0 4.0 PbF+ OU data, 2005 (0,0) band 3.0 355-397nm 2.0 energy (eV) 1.0 B2S1/2 A2S1/2 0.0 X2P1/2 280 nm -1.0 -2.0 -3.0 3.0 5.0 7.0 R(Bohr)

  40. Observation of an ionization threshold for PbF McRaven, Poopalasingam, Shafer-Ray, Chemical Physics Letters, In Progress. I.P. 7.55eV

  41. State selective ionization of PbF+ via 1+1+1 doubly-resonant multi-photon ionization. 5.0 WE HAVE DISCOVERED A NEW ELECTRONIC STATE OF PbF (tentative assignment: E'4S3/2) 4.0 PbF+ 3.0 E' 4S3/2? 2.0 436.320 1.0 A2S1/2 0.0 X2P1/2 energy (eV) -1.0 l (X→A) / nm -2.0 -3.0 436.612 3.0 5.0 7.0 R(Bohr) 440.8 442.4 l (A→E') / nm

  42. Double Resonant Ionization of PbF SIMULATION EXPERIMENT 22900.6 f (X→A) / cm-1 22889.9 f (A→E') / cm-1 f (A→E') / cm-1 22612.1 22612.1 22641.8 22641.8

  43. R2-R21 We have used our0.1cm-1 lasers toalmost isolatethe J=1/2 state! (Impossible with 1 resonant step.) JX1 7/2 1/2 3/2 5/2 9/2 R2-Q1 3/2 1/2 5/2 R2-P21 We have yet to rotationally cool. (Bigger pumps await promised DOE money. Program in limbo until Congress approvesthe Energy and Waterappropriations bill.) We now have a bluediode laser and will start scanningwith 10 MHz resolutionin the next few weeks 3/2 5/2 P1-R21 3/2 A→E' photon energy (cm-1)

  44. X→A Saturation Curve (A→E' fluence at 0.12 J/cm2) 5 Signal Intensity (a.u.) ~40mJ/cm2 of 0.1cm-1 light to saturateX→A ionization step at 437nm. A-state lifetime 3mS X→A transition may be saturatuatedwith ~15mW/mm2 diode laser radiation 0 fluence of X→A laser radiaion (mJ/cm2)

  45. radiation drivingboth A→E' and E'→PbF+ 12J/cm2 to saturateA→E'→PbF+ ionization step at 441nm. E' lifetime <5ns A→E' Saturation Curve (X→A fluence at 43 mJ/cm2) A→E' step saturated 5 ionization stepsaturated Signal Intensity (a.u.) can not be ionized with cw laser radiation 0 fluence of A→E' laser radiaion (J/cm2)

  46. TIMING FOR OPTIMIZED PbF DETECTION 437nm X→A diode laser radiation. 10mW/mm2 cw 442nm A→E'→PbF+ pulse laser radiation 10 mJ/mm2, 10-100ns 100-1000Hz 208PbF ion signal 6usec 0 2usec

  47. Current set up. 2mm (x 0.1mm) laser radiation rep rate 10 Hz PbF beam

  48. 100 mm (x 0.1mm) OPTIMIZED DETECTION OF PbF rep rate 1000 Hz PbF beam Improvement over current spectra:

  49. A 2S1/2 (F=1) M=0 |M|=1 X1 2P1/2 (F=1) |M|=1 M=0 high-field region optical polarization (create M=0 state) Raman-RF pump probe + LIF or REMPI detection region (probe M=0 state) probe -

  50. A 2S1/2 (F=1) M=0 |M|=1 X1 2P1/2 (F=1) |M|=1 M=0 high-field region optical polarization (create M=0 state) Raman-RF pump probe + LIF or REMPI detection region (probe M=0 state) probe -

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