Direct EDM search for charged hadrons at COSY

1. Direct EDM search for charged hadrons at COSY October 2, 2012 Frank Rathmann (on behalf oftheBNL-EDMandJEDI collaborations) EDM searches in Storage rings, ECT*, Trento, Italy

2. Topics • Introduction • Search forElectric Dipole Moments • Spin coherence time • First directmeasurement Resonance Method with RF E(B)-fields • Polarimetry • Conclusion Direct EDM search for charged hadrons at COSY

3. Whatcausedthe Baryon asymmetry? Carina Nebula: Largest-seen star-birth regions in the galaxy Whathappenedtothe antimatter? 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 Direct EDM search for charged hadrons at COSY

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! Direct EDM search for charged hadrons at COSY

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 Direct EDM search for charged hadrons at COSY

6. Limits for Electric Dipole Moments EDM searches - onlyupperlimits(in )up tonow: Hugeeffortsunderwaytoimprovelimits / find EDMs SensitivitytoNEW PHYSICS beyondthe Standard Model Direct EDM search for charged hadrons at COSY

7. Why also EDMs of protons and deuterons? Proton anddeuteron EDM experimentsmayprovidehighersensitivity. In particulardeuteronsmayprovide a muchhighersensitivitythanprotons. • Consensus in the theoretical community: • Essential to perform EDM measurements on different targets with similar sensitivity: • unfold the underlying physics, • explain the baryogenesis. Direct EDM search for charged hadrons at COSY

8. Search for Electric Dipole Moments NEW: EDM search in time developmentofspinin a storage ring: “Freeze“ horizontal spinprecession; watch fordevelopmentof a verticalcomponent! Direct EDM search for charged hadrons at COSY

9. Frozen spin Method Fortransverseelectricandmagneticfields in a ring ( ), anomalousspin precession isdescribedby x Magic condition: Spin alongmomentumvector Foranysignof, in a combinedelectricandmagneticmachine For(protons) in an all electric ring (magic) Direct EDM search for charged hadrons at COSY

10. 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, … Onemachinewithm Direct EDM search for charged hadrons at COSY

11. Twostorage ring projectsbeingpursued Jülich, focus on deuterons, or a combinedmachine BNL forprotons all electricmachine CW and CCW propagatingbeams (from A. Lehrach) (fromR. Talman) Direct EDM search for charged hadrons at COSY

12. Most recent: Richard Talmansconceptfor a Jülich all-in-onemachine Iron-free, current-only, magnetic bending, eliminates hysteresis B A B A Direct EDM search for charged hadrons at COSY

13. BNL Proposal 2 beamssimultaneouslyrotating in an all electricring (cw, ccw) ApprovedBNL-Proposal Submittedto DOE 11/2012Goal forprotons Circumference Technological challenges ! • Spin coherence time • Beam positioning • Continuouspolarimetry • E - fieldgradients Carry out proofofprinciple(demonstrator) experimentsatCOSY Direct EDM search for charged hadrons at COSY

14. Parameters for Jülich all-in-onemachine(R. Talmansconcept) Talman/Gebel givemaximumachievablefieldofcoppermagnetsof ~ 0.15 T. • Fitting such a machineintothe COSY buildingfavorslowermomenta. Direct EDM search for charged hadrons at COSY

15. EDM at COSY –COolerSYnchrotron Cooler andstorage ring for (polarized) protonsanddeuterons Phase space cooledinternal & extractedbeams COSY … the spin-physics machine for hadron physics Injector cyclotron Direct EDM search for charged hadrons at COSY

16. EDM at COSY –COolerSYnchrotron Cooler andstorage ring for (polarized) protonsanddeuterons Phase space cooledinternal & extractedbeams COSY … an ideal starting point for a srEDM search Injector cyclotron Direct EDM search for charged hadrons at COSY

17. “spin closed orbit vector” makes one turn “spin tune” if ║ ring stable polarization A Spin closedorbit one particle with magnetic moment Direct EDM search for charged hadrons at COSY

18. Spin coherence Weusuallydon‘tworryaboutcoherenceofspinsalong Polarization not affected! Atinjection all spinvectorsaligned (coherent) After some time, spinvectorsget out ofphaseandfullypopulatethecone CrucialforsrEDMsearchesisunderstandingandimprovingspincoherencetimes 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 Direct EDM search for charged hadrons at COSY

19. Estimateofspincoherencetimes (KolyaNikolaev) Onesourceofspincoherencearerandomvariationsofthespin tune due tothemomentumspread in the beam and israndomizedby e.g., phasespacecooling Estimate: More details in KolyaNikolaev‘stalk Spin coherence time fordeuteronsmaybelarger thanforprotons Direct EDM search for charged hadrons at COSY

20. First measurementofspincoherence time 2011 Test measurementsat COSY Polarimetry: Spin coherence time: decoherence time oscillation capture from Ed Stephenson and Greta Guidoboni Direct EDM search for charged hadrons at COSY

21. Topics • Introduction • Search forElectric Dipole Moments • Spin coherence time • First directmeasurement Resonance Method with RF E(B)-fields • Polarimetry • Conclusion Direct EDM search for charged hadrons at COSY

22. ResonanceMethodwith „magic“ RF Wien filter Avoidscoherent betatron oscillationsof beam. Radial RF-E andvertical RF-B fieldstoobservespinrotation due to EDM Approach pursuedfor a firstdirectmeasurementat COSY.  „Magic RF Wien Filter“ no Lorentz force IndirectEDM effect Tiltofprecession plane due to EDM RF E(B)-field In-plane polarization Observable: Accumulationofverticalpolarizationduringspincoherence time stored d Polarimeter (dpelastic) • Statistical sensitivityfor in therange torangepossible. • Alignmentandfieldstabilityof ring magnets • Imperfectionof RF-E(B) flipper Direct EDM search for charged hadrons at COSY

23. Operation of „magic“ RF Wien filter Radial E andvertical B fieldsoscillate, e.g., with(here). beam energy Spin coherence time maydepend on excitationand on chosenharmonics seeKolyaNikolaev‘stalk Direct EDM search for charged hadrons at COSY

24. Simulation ofresonanceMethod with „magic“ Wien filterfordeuteronsat COSY Parameters: beam energy assumed EDM E-field Linear extrapolationoffor a time periodof Preliminary, based on KolyaNikolaevsderivationofthecombinedrotationmatricesof E/B flipperand ring EDM effectaccumulates in . Direct EDM search for charged hadrons at COSY

25. Simulation ofresonanceMethod with „magic“ Wien filterfordeuteronsat COSY Parameters: beam energy assumed EDM E-field Linear extrapolationoffor a time periodof. EDM effectaccumulates in EDM effectaccumulates in Direct EDM search for charged hadrons at COSY

26. Simulation ofresonanceMethod with Magic Wien filterfordeuteronsat COSY Parameters: beam energy assumed EDM E-field Linear extrapolationoffor a time periodof. Direct EDM search for charged hadrons at COSY

27. Some polarimetry issues • srEDMexperimentsusefrozenspinmode, i.e., beam mostlypolarizedalongdirectionofmotion, • most promising ring optionsusecw & ccwbeams. • scattering on C destructive on beam andphase-space, • scatteringon C determinespolarizationofmainlyparticleswith large betatron amplitudes, and • is not capabletodetermine . • Forelasticscattering longitudinal analyzingpowersaretiny (violatesparity). Ideally, use a methodthatwoulddetermine. pCanddC polarimetry isthecurrentlyfavoredapproachforthepEDMexperimentat BNL Direct EDM search for charged hadrons at COSY

28. Exploit observables thatdepend onbeam andtargetpolarization Spin-dependent differential crosssectionfor Analyzing power Spin correlations In scattering, necessary observables are well-knownin therangeMeV (not so foror). (see David Chiladze‘stalk) Direct EDM search for charged hadrons at COSY

29. How couldone do that, determine? Detector CW CCW cell • Detector determinesofcw & ccwbeamsseparately, based on kinematics. • Alignmentoftargetpolarization along axesbymagneticfields. Leads tounwanted MDM rotations absolute no-goin EDM experiments. Suggestion 1: Use a polarizedstoragecelltarget Direct EDM search for charged hadrons at COSY

30. How couldone do that, determine? Detector Polarizedionsource(~10 MeV) • Collidetwoexternalbeamswithcwandccwstoredbeams. • Energytunabletomatchdetectoracceptance. • Polarizationcomponentsofprobinglow-energy beam canbemadelarge, wouldbeselectedbyspinrotators in thetransmissionlines. • Luminosityestimatesnecessary. Suggestion 2: Usecolliding beam fromexternalsource Direct EDM search for charged hadrons at COSY

31. How couldone do that, determine? Detector CW CCW • Requiresluminosity, -functionsat IPs shouldberathersmall. • Advantage oversuggestion 2.: supportsluminosity. • Disadvantage: Sensitivitymainlyfromtermswithand. • Detailedestimatesnecessary. Suggestion 3: Usedirectlyreactionsfromcollidingbeams Direct EDM search for charged hadrons at COSY

32. Luminosityestimateforthecollideroption Conditions: (, ,, ) Even undertheseoptimisticassumptions, event rate mightbesufficient. 4 polarimeters allowonetocollectinteractionsfrom all bunchcombinations. (see David Chiladze‘stalk) Direct EDM search for charged hadrons at COSY

33. Stepwiseapproachfor all-in-onemachinefor JEDI Time scale:Steps1and2: < 5 years Steps3and4: > 5 years Direct EDM search for charged hadrons at COSY

34. Summary • Measurementsof EDMs areextremelydifficult, but thephysicsisfantastic! • Twostorage ring projects, at BNL and Jülich • Jülich all-in-onemachinewithcopper-onlymagnets • Pursuespincoherence time measurementsatCOSY • First directEDM measurementat COSY Resonance Method with RF E(B) -fields • Optimize beam-beam polarimeterconcept • JEDI collaborationestablished Direct EDM search for charged hadrons at COSY

35. “Man mußetwasNeuesmachen, um etwasNeueszusehen.” “You have to make (create) something new, if you want to see something new” Georg Christoph Lichtenberg (1742-1799) Direct EDM search for charged hadrons at COSY

36. Spares Direct EDM search for charged hadrons at COSY

37. Technicallydriventimelinefor all-electricpEDMat 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” Direct EDM search for charged hadrons at COSY

38. 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 Direct EDM search for charged hadrons at COSY

39. ResonanceMethodwith RF E-fields spin precession governedby: (* restframe) verticalpolarization RF E-field • Two situations: •  EDM effect •  no EDM effect stored d Polarimeter (dpelastic) • This way, the EDM signalisaccumulatedduringthecycle. • Statistical improvementoversingle turn effectisabout: . • Brings us in therangefor. • But: Flippingfields will leadtocoherent betatron oscillations, withhardto handle systematics. Direct EDM search for charged hadrons at COSY

40. Simulation ofresonanceMethodwith RF E-fieldsfordeuteronsat COSY Parameters: beam energy assumed EDM E-field E-fieldreversedevery Constant E-field Numberofturns Numberofturns Direct EDM search for charged hadrons at COSY

41. Simulation ofresonanceMethodwith RF E-fieldsfordeuteronsat COSY Parameters: beam energy assumed EDM E-field Linear extrapolationoffor a time periodof EDM effectaccumulates Polarimeter determines Numberofturns Direct EDM search for charged hadrons at COSY

42. Symmetries Physical laws are invariant under certain transformations. • T-Symmetry: C-parity(or Charge parity): • Changessignof all quantizedcharges • electrical charge, • baryon number, • lepton number, • flavor charges, • Isospin (3rd-component) Parity: Direct EDM search for charged hadrons at COSY

43. Magic condition: Protons Case 1: fieldonly Direct EDM search for charged hadrons at COSY

44. Magic condition: Protons Case 2: andfields magicenergy magicenergy Direct EDM search for charged hadrons at COSY

45. Magic condition: Deuterons andfields Direct EDM search for charged hadrons at COSY

46. Magic condition: Helions andfields Direct EDM search for charged hadrons at COSY