1 / 26

Electric dipole moment searches

Electric dipole moment searches. Peter Fierlinger. Outline. Motivation Different systems to search for electric dipole moments (EDMs) Examples. P. Fierlinger – MeNu2013. Electric dipole moment. Magnetic moment. A non- zero particle EDM violates P … and T (time reversal symmetry)

tomas
Download Presentation

Electric dipole moment searches

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electricdipolemomentsearches Peter Fierlinger

  2. Outline Motivation Different systemstosearchforelectricdipolemoments (EDMs) Examples P. Fierlinger – MeNu2013

  3. Electricdipolemoment Magneticmoment A non-zeroparticle EDM violates P … and T (time reversal symmetry) … assuming CPT conservation, also CP - Purcell and Ramsey, PR78(1950)807 EDM + P. Fierlinger – MeNu2013

  4. History L-R symmetric n p MSSM ~1 Ramsey & Purcell (1950) n n+Hg e- Xe n Multi- Higgs e-(Tl) EDM limits [e.cm] n Hg `01 Hg `09 MSSM ~/ Atoms e- SM neutron SM electron

  5. Neutron EDM andthe SM CP violationfrom CKM Strong Interaction CP-odd term in Lagrangian: KhriplovichZhitnitsky (1986), McKellar et al., (1987) E.g. Pospelov, Ritz, Ann. Phys. 318(2005)119 M. Pospelov, et al., Sov. J. Nucl. Phys. 53, 638 (1991) • Neutron EDM dn 10-32ecm(de < 10-38ecm) • dn much more difficult to calculate, but still small Strong CP problem T. Mannel, N. Uraltsev, Phys.Rev. D85 (2012) 096002 P. Fierlinger – MeNu2013

  6. Baryon asymmetry Observed: nB / nγ ~ 6x 10-10 (BBN, CMB) Expected: nB / nγ~ MUCH smaller e.g. astro-ph/0603451 ‚Ingredients‘ tomodelbaryogenesis: Sakharov criteria JETP Lett. 5 (1967) 24 Remarks: e.g. Cirigliano, Profumo, Ramsey-Musolf JHEP 0607:002 (2006) • Beyond-SM physicsusuallyrequires large EDMs • EDMs andBaryogenesis via Leptogenesis? • Also otheroptions w/o new CP violationpossible(Kostelecky, CPT) • SUSY: small CPV phases, heavy masses, cancellations? • What do welearnfrom an EDM? • Different measurementsareneeded! P. Fierlinger – MeNu2013

  7. Physicsbehind EDMs de d d dq  Cqe Cqq dq gNN CS,P, T Neutron, proton ~ Leptons See e.g. Pospelov, Ritz, Ann. Phys. 318(2005)119 Schiff-Moment  Z² Ions Schiff-Moment  Z³ Diamagnetic atoms Paramagneticatoms, polar / chargedmolecules P. Fierlinger – MeNu2013

  8. Atom EDM Schiff moment: Non-perfectcancellation of Eext in atomicshell Paramagneticatoms ~ electron EDM Relativisticeffects L. Schiff, Phys. Rev. 132, 2194 (1963) Sandars, 1968 Diamagneticatoms ~ nuclear EDM Finite sizeofnucleusviolatesSchiff‘stheorem Eext Schiff 1963; Sandars, 1968; Feinberg 1977; ... - 2010 Large enhancements also withdeformednuclei (Ra, Rn, also Fr, Ac, Pa) P. Fierlinger – MeNu2013

  9. Atomiceffects Contributionstoatomic EDMs: • 13 (model-dependent) parameters • TeV-scale CP oddphysics, nucleonlevel, nucleus-level • Only 8 types of experiments Illustration: T. Chuppet al., to be published *) See also J. Engel, M. J. Ramsey-Musolf, U. van Kolck, Prog. Part. Nucl. Phys. 71, 21 (2013) gπ1 gπ0 P. Fierlinger – MeNu2013

  10. Measuring the neutron EDM (RAL/SUSSEX/ILL experiment) Ultra-coldneutrons (UCN) trappedat 300 K in vacuum Ekin < 250 neV  > 50 nm T ~mK Storage ~ 102 s B0 ~ 0.5 m P. Fierlinger – MeNu2013

  11. Ramsey‘smethod Particle beam ortrappedparticles Polarization E 1-L („detuning“) EDM changesfrequency: P. Fierlinger – MeNu2013

  12. Clock-comparisonexperiment - Neutrons and199Hg stored in the same chamber - Gravity changes center of mass! B =1 T ( + smallverticalgradient) Physical Review Letters  97 (2006) 131801. Illustration (2008 data) Analysis using the gradient: B0 down B0up dn < 2.9 x 10-26 e cm Applied Gradient Requirement: 199Hg-EDM must besmall: (btw., this also limitsotherparameters, e.g CS, CT...): dHg < 3.1 x 10-29e cm Frequencyratio Hg-EDM: W. C. Griffith et al., PRL 102, 101601 (2012) P. Fierlinger – MeNu2013

  13. Neutron andprotonexperiments nEDM Cryo EDM ILL Crystal EDM FRM-II EDM JPARC NIST Crystal PNPI/ILL PSI EDM SNS EDM TRIUMF/RNPC pEDM Jülich BNL Method 4He Solid sD2 sD2 Cold beam Turbine sD2 4He 4He B and E field ring Electrostatic ring Goal (x10-28ecm) ~ 50; 2. < 5 < 100 < 5 < 10 < 10 1. ~ 100; 2. < 10 1. ~ 50; 2. < 5 < 5 < 10 1. R&D; 2. 10-24; 3. 10-29 10-29 Comments Larger revisionstocome Diffraction in crystal: large E AdjustableUCN velocity Special UCN handling R&D E = 0 referencecell Phase 1 takesdata Sophisticatedtechnology Phase II at TRIUMF Stepwiseimprovements Completelynoveltechnology P. Fierlinger – MeNu2013

  14. ‚Currentgeneration‘ improvements PSI (taken from B. Lauss, K. Kirch), for actual numbers see PSI EDM talk PNPI/ILL (taken from A. Serebrov, 2013): • UCN density measured in a 25l volume • extrapolated to t=0 • at PSI area West-1 • 2010 ~0.15 UCN/cm3 • 2011 ~18 UCN/cm3 • 2012 ~23 UCN/cm3 • correct for detector foil transmission • status (4/2013) >33 UCN/cm3 in storage experiment (-> this is an extrapolation) • < 2 UCN/cm3 in EDM experiment UCN density 3-4 ucn/cm3 (MAM position)Electric field 10 kV/cm T(cycle) = 65 s ...new electric field 20 kV/cm δDedm ~ 5∙10-25 e∙cm/day ~ 2014: EDM position at PF2 1∙10-26 e∙cm/100 days δDedm ~ 2.5∙10-25 e∙cm/day 14 P. Fierlinger – MeNu2013

  15. ‚Next generation‘ Most criticalfornextgenerationexperiments: ‚geometricphases‘ Example: Dipole fields in EDM chambers 20 pT in 3 cm ~ 5 x errorbudget! SQUID measurements of Sussex EDM electrodes @ PTB Berlin Pendlebury et al., Phys. Rev. A 70, 032102 (2004) Magneticfieldrequirements for 10-28 ecm – levelaccuracy: ~ fTfielddrifterror, ~ < 0.3 nT/m avg. gradients df ~ 4.10-27 ecm (199Hg geom. phase) dn~ 1-2.10-28ecm(UCN geom. phase) ~ 0.3 m demagnetized: 20 pT pp 200 pT pp Statistics: 103UCN/cm3 ~ 1 year Further: P. G. Harris et al., Phys. Rev. A 73, 014101 (2006), also: G. Pignol, arXiv:1201.0699 (2012). P. Fierlinger – MeNu2013

  16. New sourcesof UCN Superthermal solid D2or superfluid 4He-II SD2: Molceularexcitationsusedto cool neutronstozeroenergy - similar: ILL,LANL, Mainz, NCSU, PNPI, PSI, TUM … 4He:ILL, KEK, SNS, TRIUMF, … Goal of mostsources: 10³ UCN /cm³ in experiment P. Fierlinger – MeNu2013

  17. Magneticfields • The smallest extended size • field and gradient on earth • < 100 pT/m gradient in 0.5 m3 • At FRM-II EDM setup: fields designed and measured -this technology is ready and available! z = - 0.5 m z = 0 m (center) z = 0.5 m x [m] [nT] SQUID offset in z not corrected y [-0.5 m – 0.5 m] P. Fierlinger – MeNu2013

  18. Next generationneutron EDMs • E.g. at FRM-II (reactor): • ‚Conventional‘, double chamber • UCN velocitytuning • Cs, 3He, 199Hg, 129Xe (co)magnetometers • Readyfor UCN in 1 year • E.g. at SNS (spallation): • Cryogenic, double chamber • Neutron detection via spindependent • 3He absorptionandscintillation • 3He co-magnetometry • In the future... againnEDMwith a cold beam? • Pulse structureand strong peakflux: • Cold-beam-EDM atlong-pulse-neutron source (ESS) couldbecompetitive? (Piegsa, PRC, soon...) • Re-acceleratedpolarized UCN with pulse-structure? (PF, in prep.) P. Fierlinger – MeNu2013

  19. Next generationnucleon EDMs • Proton, deuteron, ... EDM • Chargedparticle EDM searchesrequire the development of a newclass of high-precisionstorage rings • Projectedsensitivity ~ 10-29ecm: … tests to < 10-13! • Currently 2 approaches: • JEDI collab.: startingwith COSY ring, development in stages • E, B fields • BNL: completelyelectrostatic, new design • all-electricring • Requirements: • Electricfieldgradients 17 MV/m (possible) • Spin coherencetimes > 1000 s (200s demonstratedat Jülich) • Continuouspolarimetry < 1 ppm error(demonstratedat Jülich) • Spin trackingsimulations of 109particlesover 1000 s P. Fierlinger – MeNu2013

  20. Proton EDM in ‚magic‘ ring - Frozen horizontal spinprecession: p || s - EDM turns s out of plane P, S aligned V. Bargmann, L. Michel and V. L. Telegdi, Phys. Rev. Lett. 2 (1959) 435. • Magic ring: • - Purelyelectric ring onlyfor G > 0 • - E and B ring forother isotopes Electrostatic ring proposal at BNL Figures: H. Stroeher P. Fierlinger – MeNu2013

  21. Ra Oven: Zeeman Slower EDM probe Optical dipole trap Octupoledeformations: 225Ra Enhancement factors: EDM (225Ra) / EDM (199Hg) ~ 103 Why trap 225Ra atoms: efficient use of the rare 225Ra atoms high electric field (> 100 kV/cm) long coherence times ~ 100 s negligible “v x E” effect Nuclear Spin = ½ t1/2= 15 days Schiff moment of 225Ra, Dobaczewski & Engel, PRL (2005) Magneto-optical trap • Goal ~ 10-28ecm • Main issue: statistics • (Project X?) MOT: Guest et al., PRL (2007) Dipole trap: Trimble et al. (2010) Figures: Z.-T. Lu P. Fierlinger – MeNu2013

  22. Lepton EDM measurements • Best limits: • Mainlyparamagneticsystemsand polar molecules • Cs, Tl, YbF: de < 1.05.10-27ecm (E. Hinds et al.) • Soon: ThO – currentlytakingdata • Molecules, molecularions, solids: PbO, PbF, HBr, BaF, HgF, GGG, Gd2Ga5O12 etc. • dGGG ~ < 10-24ecm • d < 1.8 . 10-19 (90%) ecmfromg-2 • d < 1.7 . 10-17 (90%) ecmfromZ • Diamagneticatoms also • contributeto such limits! Shapiro, Usp. Fiz. Nauk., 95 145 (1968) Tl, YbF limits together, courtesy T. Chupp (2013) P. Fierlinger – MeNu2013

  23. The ACME experiment • ThO molecules: • 100 GV/cm internal electric field due to level structure, • polarizable with very small lab-field • Small magnetic moment, therefore less sensitive to B-field quality • High Z: enhancement • Well understood system • Lasers to select states • High statistics: • strong cold beam Status: takingdatawith 10-28ecm /day Figures: J. Doyle P. Fierlinger – MeNu2013

  24. Summary New EDM experiments are highly sensitive probes for new physics Several experiments must be performed to understand the underlying physics. (Then, also a measured limit may be a discovery...) Experimental techniques span from table top AMO - solid state - low temperature – accelerators - neutron physics Next generation precision within next 2 years: nEDM ~ few 10-27ecm atoms ~ < 1.10-29ecm (ThO, 199Hg, 129Xe) 6 years: nEDM ~ few 10-28ecm atoms - hard to predict ... Note: my nEDM time estimate stayed constant since 2009 P. Fierlinger – MeNu2013

  25. New concepts? Re-acceleration of UCN Apossibilitytoproduceextremely high brightness ‚cold‘ neutronbeams: conceptdemonstrated(Rauch et al.) Next step: Perfectpolarization (PF et al.) S. Mayer et al., NIM A 608 (2009) 434–439 Again: nEDMmeasuredwith a cold beam? Beam-EDM atlong-pulse-neutron sourcecouldbecompetitive(Piegsa et al., tobepublishedsoon) Why not use a combination: perfectlypolarized, re-accelerated high brightness beam withextremelywellknown time structurefor in-beam EDM?

  26. Supersymmetry More sourcesof CP violation ~ EDMs at 1 looplevel MSSM example: MSSM for M = 1 TeV, tan =3 Hg EDM ~ exp. Limit! Bosoncoupling Pospelov, Ritz, Ann. Phys. 318(2005)119 • Consequences • smallphases: • problemforbaryogenesis • cancellations: requirestuning • heavy masses Higgsinomassphase P. Fierlinger – MeNu2013

More Related