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EDMs in Storage Rings: Powerful Probes of Physics Beyond the SM and of CP-Violation

Colloquium Berkeley, 26 April 2004. EDMs in Storage Rings: Powerful Probes of Physics Beyond the SM and of CP-Violation. Yannis K. Semertzidis Brookhaven National Laboratory. EDMs: Why are they important? Our Universe: The Symmetry that isn’t EDM Experimental Techniques

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EDMs in Storage Rings: Powerful Probes of Physics Beyond the SM and of CP-Violation

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  1. Colloquium Berkeley, 26 April 2004 EDMs in Storage Rings: Powerful Probes of Physics Beyond the SM and of CP-Violation Yannis K. Semertzidis Brookhaven National Laboratory • EDMs: Why are they important? • Our Universe: The Symmetry that isn’t • EDM Experimental Techniques • EDMs in Storage Rings • Prospects of the Field

  2. Questions Physicists Ask:

  3. A Permanent EDM Violates both T & P Symmetries:

  4. + - + - Phenom.: only the component along the spin survives... Spin is the only vector…

  5. + T - + - P - + A Permanent EDM Violates both T & P Symmetries:

  6. T P A Permanent EDM Violates both T & P Symmetries:

  7. T OK P OK 1st order Stark effect. Forbidden! 2nd order Stark effect. Allowed! Reality Check: Induced EDMs…

  8. T P Reality Check: MDMs are Allowed…

  9. CPT T-Violation CP-Violation Andrei Sakharov 1967: CP-Violation is one of three conditions to enable a universe containing initially equal amounts of matter and antimatter to evolve into a matter-dominated universe, which we see today….

  10. Flashback Before 1929: • Universe is Static-Eternal • Cosmological Constant is Invented to Stabilize it! • Dirac Equation 1928: • g=2 for Point-like, Spin ½ Particles • Negative Energy States

  11. Hubble 1929: • Universe is Expanding • …If the Universe Expands… a Beginning and a BIG BANG! • Km/MPa/s or 10-18s-1 • Discovery of Positron by Anderson: 1933

  12. At Accelerators: • 1955: Antiproton Discovery at Berkeley • 1956: Antineutron Discovery • 1957: Parity Violation, Lee-Yang • 1964: CP-Violation at Brookhaven • Universe: Matter Dominated; Initial Condition Maintained by B, L Number Conservation.

  13. The History of Our Universe

  14. The History of Our Universe Nucleosynthesis builds nuclei up to He Ionized gases Today’s Cold Universe… Matter Everywhere! No Antimatter. How did it Happen?

  15. Andrei Sakharov 1967: • Three conditions to enable a universe containing initially equal amounts of matter and antimatter to evolve into a matter-dominated universe, which we see today: • Proton Decay (Baryon Number Violation) • CP-Violation • Universe Undergoes A Phase of Extremely Rapid Expansion

  16. Extension of the SM Needed? • SM: CP-Violation not Enough by Several Orders of Magnitude for Baryogenesis • Leptogenesis: CP-Violation in Neutrino Mixing? • Heavy, Weakly Interacting, Right-Handed Neutrinos Produced in Early Universe • Their Decays Produces Lepton Number Asymmetry. • Further Interactions Conserving B-L Convert it to Baryon Number Asymmetry

  17. SM Versus SUSY: SM: One CP-Violating Phase (CKM). 42 CP-Violating Phases! SUSY:

  18.  la Fortson d ~

  19. E Small Signal + Compare the Zeeman Frequencies When E-field is Flipped: - Usual Experimental Method

  20. Schiff Theorem:A Charged Particle at Equilibrium Feels no Force……An Electron in a Neutral Atom Feels no Force Either: …Otherwise it Would be Accelerated…

  21. Neutron EDM Vs Year

  22. Neutron EDM at LANSCEAiming for a Factor of 50

  23. 3

  24. Q=CV

  25. S. Lamoreaux at “Lepton Moments”, June 2003 E=5MV/m, T=108s R&D

  26. Cost of the n-EDM Experiment at LANSCE • $10M for the experimental apparatus • $9M for the Beamline • R&D? • Total $19M plus R&D

  27. Schiff Theorem:A Charged Particle at Equilibrium Feels no Force……An Electron in a Neutral Atom Feels no Force Either. However: …the net E-field is not zero!

  28. Electron EDM 10-20 Cs 10-22 Cs 10-24 Xe* Hg Experimental Limit on de (e .cm) Cs 10-26 Tl Tl Tl ?? 10-28 10-30 1960 1970 1980 1990 2000 2010

  29. Current Atomic EDM Limits • Paramagnetic Atoms, 205Tl: electron |de| < 1.610-27e·cm (90%CL) PRL 88, 071805 (2002) • Diamagnetic Atoms, 199Hg Nucleus: |d(199Hg)| < 2.110-28e·cm (95%CL) PRL 86, 2505 (2001)

  30. Electric Dipole Moments in Storage Rings e.g. 1T corresponds to 300 MV/m!

  31. Spin Precession in g-2 Ring(Top View) Momentum vector m Spin vector

  32. Spin Precession in g-2 Ring(Top View) Momentum vector m Spin vector

  33. The Muon Storage Ring: B ≈ 1.45T, Pμ≈3.09 GeV/c • Inner Ring of Detectors • High Proton Intensity from AGS • Muon Injection

  34. 4 Billion e+ with E>2GeV

  35. Indirect Muon EDM limit from the g-2 Experiment z y s β x B Ron McNabb’s Thesis 2003:

  36. Canceling g-2 with a Radial E-field z B E y s β x

  37. Radial E-field to Cancel the g-2 Precession • Radial E-Field: The method works well for particles with small anomalous magnetic moment a, e.g. Muons (a = 0.0011), Deuterons (a = -0.143), etc.

  38. Momentum vector Spin vector Spin Precession in g-2 Ring(Top View) m

  39. Momentum vector Spin vector Spin Precession in EDM Ring(Top View) m

  40. The muon spin precesses vertically (Side View)

  41. The muon spin precesses vertically (Side View)

  42. Two Major Ideas: • Radial E-field to Cancel the g-2 Precession • Injecting CW and CCW • Sensitivity: 10-24 e·cm statistical (1 yr, 0.75MW) • Sensitivity: 10-27 e·cm systematic error • Muon EDM LOI: (http://www.bnl.gov/edm) to J-PARC.

  43. Muon EDM Letter of Intent to J-PARC/Japan, 2003 † † # • †Spokesperson • # Resident Spokesperson

  44. Expected Muon EDM Value from a

  45. Predictions in Specific Models 50 effect at 10-24 ecm Exp. Sensitivity! The predicted value for the electron is 10 times less than the current experimental limit.

  46. Predictions in Specific Models T. Feng, et al., hep-ph/0305290 “Lepton Dipole Moments and Rare Decays in the CP-Violating MSSM with Non-Universal Soft-Supersymmetry Breaking” Experimental Goal

  47. g-2 Values • Electron 0.0016 done • Muon 0.0016 doing • Proton 1.8 ------ • Deuteron -0.15 OK!

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