EDM Searches in storage rings

1. EDM Searches in storage rings June 26, 2012 Frank Rathmann on behalf ofthe BNL-EDM and JEDI collaborations Workshop on existing and future Projects PNPI-Jülich 24-28 June 2012. Gatchina

2. Topics • Why EDMs? • Search for EDMs usingstoragerings • Twoprojects, at BNL andJülich • Spin coherence time • First directmeasurement Resonance Method with RF E(B) -fields • Summary EDM Searches in storage rings

3. Whatcausedthe Baryon asymmetry? Carina Nebula: Largest-seen star-birth regions in the galaxy • Sakharov (1967):Three conditions for baryogenesis • B number conservation violated sufficiently strongly • C and CP violated,B and anti-Bs with different rates • Evolution of universe outside thermal equilibrium EDM Searches in storage rings

4. Electric Dipole Moments (EDMs) Permanent EDMs violate parity P and time reversal symmetry T Assuming CPT to hold, combined symmetry CP violated as well. EDMs arecandidatestosolvemysteryof matter-antimatter asymmetry  mayexplainwhywearehere! EDM Searches in storage rings

5. Historyofneutron EDM limits • Smith, Purcell, Ramsey PR 108, 120 (1957) • RAL-Sussex-ILL(dn 2.9 10-26ecm) PRL 97,131801 (2006) Adoptedfrom K. Kirch EDM Searches in storage rings

6. Limits for Electric Dipole Moments EDM searches - onlyupperlimitsuptonow (in ecm): Hugeeffortsunderwaytoimprovelimits / find EDMs SensitivitytoNEW PHYSICS beyondthe Standard Model 485. WE-Heraeus-Seminar (July 0406, 2011) SearchforElectric Dipole Moments (EDMs) at Storage Rings http://www2.fz-juelich.de/ikp/edm/en/ EDM Searches in storage rings

7. Why also EDMs of protons and deuterons? Proton anddeuteron EDM experimentsmayprovideone order highersensitivity. In particularthedeuteronmayprovide a muchhighersensitivitythanprotons. • Consensus in the theoretical community: • Essential to perform EDM measurements on different targets (p, d, 3He) with similar sensitivity: • unfold the underlying physics, • explain the baryogenesis. EDM Searches in storage rings

8. Search for Electric Dipole Moments NEW: EDM search in time developmentofspinin a storage ring: “Freeze“ horizontal spinprecession; watch fordevelopmentof a verticalcomponent! EDM Searches in storage rings

9. The frozen spin Method Fortransverseelectricandmagneticfields in a ring ( ), anomalousspin precession isdescribedby x Magic condition: Spin alongmomentumvector Foranysignof G, in a combinedelectricandmagneticmachine For G>0 (protons) in an all electric ring (magic) EDM Searches in storage rings

10. Magic condition: Protons E-fieldonly EDM Searches in storage rings

11. Magic condition: Deuterons E and B fields EDM Searches in storage rings

12. Magic condition: Helions E and B fields EDM Searches in storage rings

13. Search for Electric Dipole Moments NEW: EDM search in time developmentofspinin a storage ring: “Freeze“ horizontal spinprecession; watch fordevelopmentof a verticalcomponent! A magicstorage ring forprotons (electrostatic), deuterons, … Onemachinewith r ~ 30 m EDM Searches in storage rings

14. Twostorage ring projectsbeingpursued Jülich, focus on deuterons, or a combinedmachine BNL forprotons all electricmachine CW and CCW propagatingbeams (from A. Lehrach) (fromR. Talman) EDM Searches in storage rings

15. BNL Proposal 2 beamssimultaneouslyrotating in a ring (CW, CCW) ApprovedBNL-Proposal Submittedto DOEGoal forprotons Circumference ~ 200 m Technological challenges ! • Spin coherence time (1000 s) • Beam positioning (10 nm) • Continuouspolarimetry (< 1ppm) • E - fieldgradients (~ 17MV/m at 2 cm) Carry out proofofprincipleexperiments (demonstrators) atCOSY EDM Searches in storage rings

16. EDM at COSY –COolerSYnchrotron Cooler and storage ring for (polarized) protons and deuterons p = 0.3 – 3.7 GeV/c Phase space cooled internal & extracted beams COSY … the spin-physics machine for hadron physics Injector cyclotron EDM Searches in storage rings

17. EDM at COSY –COolerSYnchrotron Cooler and storage ring for (polarized) protons and deuterons p = 0.3 – 3.7 GeV/c Phase space cooled internal & extracted beams COSY … an ideal starting point for a srEDM search Injector cyclotron EDM Searches in storage rings

18. “spin closed orbit vector” makes one turn “spin tune” if ║ ring stable polarization A Spin closedorbit one particle with magnetic moment EDM Searches in storage rings

19. Spin coherence Weusuallydon‘tworryaboutcoherenceofspinsalong Polarization not affected! Atinjection all spinvectorsaligned (coherent) After some time, spinvectorsget out ofphaseandfullypopulatethecone Situation very different, whenyou deal with Longitudinal polarizationvanishes! In an EDM machinewithfrozenspin, observation time is limited. Atinjection all spinvectorsaligned After some time, thespinvectorsare all out ofphaseand in the horizontal plane EDM Searches in storage rings

20. Estimateofspincoherencetimes (N.N. Nikolaev) Onesourceofspincoherencearerandomvariationsofthespin tune due tothemomentumspread in the beam and israndomizedby e.g., electroncooling Estimate: Spin coherence time fordeuteronsmaybe ~100 larger thanforprotons EDM Searches in storage rings

21. First measurementofspincoherence time 2011 Test measurementsat COSY Polarimetry: Spin coherence time: 5 s 25 s 5 s decoherence time oscillation capture fromEd Stephenson and Greta Guidoboni EDM Searches in storage rings

22. ResonanceMethodwith RF E-fields spin precession governedby: (* restframe) verticalpolarization RF E-field • Twosituations: • B*=0  By= ER (= 70 G for ER=30 kV/cm) EDM effect • E*=0  ER= -Byno EDM effect stored d Polarimeter (dpelastic) This way, theEDM signalisaccumulatedduringthecycle. Statistical improvementoversingle turn effectisabout: . Brings us in the 10-24ecmrangefordd EDM Searches in storage rings

23. Simulation ofresonanceMethodwith RF E-fieldsfordeuteronsat COSY Parameters: beam energyTd=50 MeV LRF=1 m assumed EDM dd=10-20ecm E-field 10 kV/cm E-fieldreversedevery -/(G)  21 turns Constant E-field Numberofturns Numberofturns EDM Searches in storage rings

24. Simulation ofresonanceMethodwith RF E-fieldsfordeuteronsat COSY Parameters: beam energyTd=50 MeV assumed EDM dd=10-20ecm E-field 10 kV/cm Linear extrapolationoffor a time periodofsc=1000 s (=3.7108turns) EDM effectaccumulates Polarimeter determines Px, PyandPz Numberofturns EDM Searches in storage rings

25. ResonanceMethodwith„magic“ Wien filter Approach pursuedfor a firstdirectmeasurementatCOSY. Avoidstransversemotionof beam in RF device! Radial RF-E andvertical RF-B fieldstoobservespinrotation due to EDM E*=0  ER= -By „Magic RF Wien Filter“ no Lorentz force „Indirect“ EDM effect Tiltofprecession plane due to EDM RF E(B)-field Transversepolarization Observable: Accumulationofverticalpolarizationduringspincoherence time stored d Polarimeter (dpelastic) Statistical sensitivityfordd in therange 10-23to10-24ecmrangepossible Alignmentandfieldstabilityof ring magnets Imperfectionof RF-E(B) flipper EDM Searches in storage rings

26. Operation of „magic“ Wien filter Radial E andvertical B fieldsoscillate, e.g., with(here). Spin coherence time maydepend on excitationand on chosenharmonics EDM Searches in storage rings

27. Simulation ofresonanceMethod with Magic Wien filterfordeuteronsat COSY Parameters: beam energyTd=50 MeV LRF=1 m assumed EDM dd=10-24ecm E-field30 kV/cm Linear extrapolationoffora time periodofsc=1000 s (=3.7108turns) EDM effectaccumulates in Py EDM Searches in storage rings

28. Simulation ofresonanceMethod with Magic Wien filterfordeuteronsat COSY Parameters: beam energyTd=50 MeV LRF=1 m assumed EDM dd=10-24ecm E-field30 kV/cm Linear extrapolationoffora time periodofsc=1000 s (=3.7108turns) EDM effectaccumulates in Py EDM Searches in storage rings

29. Simulation ofresonanceMethod with Magic Wien filterfordeuteronsat COSY Parameters: beam energyTd=50 MeV LRF=1 m assumed EDM dd=10-24ecm E-field30 kV/cm Linear extrapolationoffora time periodofsc=100000 s (=3.71010turns) EDM effectaccumulates in Py EDM Searches in storage rings

30. TechnicallydriventimelineforpEDMat BNL 15 18 12 13 14 16 17 19 20 21 • Two years R&D/preparation • One year final ring design • Two years ring/beam-line construction • Two years installation • One year “string test” EDM Searches in storage rings

31. Stepwiseapproach in the JEDI project Time scale: Steps 1 and 2: < 5 years Steps 3 and 4: > 5 years EDM Searches in storage rings

32. srEDM cooperations International srEDM Network Institutional (MoU) and Personal (Spokespersons …) Cooperation, Coordination srEDMCollaboration (BNL) (spokespersonYannisSemertzidis) JEDI Collaboration (FZJ)(spokespersons: A. Lehrach, J. Pretz, F.R.) • Common R&D • RHICEDM-at-COSY • Beam Position Monitors Polarimetry • (…) Spin Coherence Time • Cooling • Spin Tracking (…) Study Group First directmeasurement Ring Design DOE-Proposal(submitted) CD0, 1, … HGF Application(s) pEDM Ring at BNL JEDI EDM Searches in storage rings

33. EDM Workshop at ECT* (Trento) October 1-5, 2012 http://www.ectstar.eu/ • Organizingcommittee • Jülich • Hans Ströher h.stroeher@fz-juelich.de • Frank Rathmann f.rathmann@fz-juelich.de • Andreas Wirzbaa.wirzba@fz-juelich.de • Brookhaven • Mei Baimbai@bnl.gov • William Marciano marciano@bnl.gov • Yannis Semertzidis yannis@bnl.gov EDM Searches in storage rings

34. Summary • Measurement of EDMs extremelydifficult, but thephysicsisfantastic! • Twostorage ring projects, at BNL and Jülich • Pursuespincoherence time measurementsatCOSY • First directmeasurementat COSY Resonance Method with RF E(B) -fields • New JEDI collaborationestablished EDM Searches in storage rings

35. Georg Christoph Lichtenberg (1742-1799) “Man mußetwasNeuesmachen, um etwasNeueszusehen.” “You have to make (create) something new, if you want to see something new” EDM Searches in storage rings

36. Spare transparencies EDM Searches in storage rings

37. Mega-ton Detectors Stability (p-decay) Neutrino physics LHC Super-beam Factories Intensity Mass (Higgs) Supersymmetry Extra Dimensions Energy The Scientific Frontiers to address well-defined questions about the physics of our World CKM QGP nMass CosmicParticles Dark Matter Dark Energy Dedicated Small-scale Facilities Precision Cosmic Underground Labs, Non-accelerator Symmetries (TRV, EDM) Complexity RHIC Matter  Materials QCD phasediagram Radiation Facilities EDM Searches in storage rings

38. COSY: Concept for Snake • Shouldallowfor flexible useattwolocations • Fast ramping (< 30s), withinjectionofPy • Cryogen-freesystem • Shouldbeavailable in 2012 ANKE ANKE PAX PAX EDM Searches in storage rings

39. Onebackupslideforolrov EDM Searches in storage rings

40. snakes there is an for every point of the orbit Snakes (non-vertical B field) affect flippers ramping through a resonance reverses spin manipulation 180o spin closed orbit EDM Searches in storage rings

41. cooled beam ring acceptance target lost Machineacceptance In an ideal machine (like TSR-HD) → Single-Coulomb scattering at the target dominates beam loss K. Grigoriev et al., NIMA 599,130 (2009) EDM Searches in storage rings

42. IBeam time Future: Time Reversal Invariance Test COSY-TRIC: P-even, T-odd COSY used as accelerator and detector: Total polarization correlation coefficient Ay,xzleads to relative difference of current slopes PAX Milestone: Operation of Precision BCT with I/I<10-4 EDM Searches in storage rings

43. Need for a highprecision BCT Possiblesolution: CryogenicCurrentComparator, read out bylow-temperature super-conductingquantuminterferencedevice • Status TRI Test at COSY • Slow fluctuations in themeasured BCT signalexceedthe noise band at higher frequencies D. EversheimHyperfine Interact 193 (2009) A. Steppke, IEEE Trans. Appl. Superc. (2009) Highestresolutionachieved: 250 pA/Hz EDM Searches in storage rings

44. Freezing Spin Precession with E-Fields • G > 0 for γ> 1, if only electric fields are applied • Magic momentum for protons: p = 700.74 MeV/c μp / μN=2.792 847 356 (23) Gp= 1.7928473565 μd / μN = 0.857 438 2308 (72)  Gd= -0.14298727202 μHe-3 / μN = -2.127 497 718 (25) G3He= -4.1839627399 Nuclear magneton: μN =eħ / (2mpc) = 5.050 783 24 (13) · 10-27 J T-1 EDM Searches in storage rings