Electric dipole moments (EDM) experiments Making progress in
9 February 2015 EP-Seminar, CERN The status of EDM experiments and the Storage Ring Proton EDM Yannis Semertzidis, CAPP/IBS at KAIST Electric dipole moments (EDM) experiments Making progress in Electron, Neutron, & Storage ring Proton EDM experiments Y. Semertzidis, CAPP/IBS, KAIST
South Korea: New Institute with emphasis in basic science, $0.5B/year Y. Semertzidis, CAPP/IBS, KAIST IBS/CAPP: Center for Axion and Precision Physics research
Strong CP-Problem Axion dark matter search: State of the art axion dark matter experiment in Korea Collaborate with ADMX, CAST Proton Electric Dipole Moment Experiment Storage ring proton EDM Muon g-2, mu2e, etc. Y. Semertzidis, CAPP/IBS, KAIST Y. Semertzidis, CAPP/IBS, KAIST
CAPP Group Several more Research Fellows signed up already Y. Semertzidis, CAPP/IBS, KAIST Physics at the Frontier, pursuing two approaches:
Energy Frontier (LHC,) Precision Frontier (g-2, mw, B, EDM, ,) which are complementary and inter-connected.The next SM will emerge with input from both approaches. Physics reach of magic pEDM (Marciano)
Sensitivity to new contact interactions: 1000 TeV Sensitivity to SUSY-type new Physics: The proton EDM at 10-29ecm has a reach of>300TeV or, if new physics exists at the LHC scale, < rad CP-violating phase; an unprecedented sensitivity level. The deuteron EDM sensitivity is similar. 6 Matter-antimatter asymmetry points to BSM CP-violation
We see: From the SM: Y. Semertzidis, CAPP/IBS, KAIST Cosmological inventory
Y. Semertzidis, CAPP/IBS, KAIST Y. Semertzidis, CAPP/IBS, KAIST
Purcell and Ramsey: The question of the possible existence of an electric dipole moment of a nucleus or of an elementary particlebecomes a purely experimental matter Phys. Rev. 78 (1950) Y. Semertzidis, CAPP/IBS, KAIST Short History of EDM 1950s neutron EDM experiment (Ramsey & Parcel), looking for parity violation After P-violation was discovered it was realized EDMs require both P & T-violation 1960s EDM searches in atomic systems 1970s Indirect Storage Ring EDM method from the CERN muon g-2 exp. 1980s Theory studies on systems (molecules) w/ large enhancement factors 1990s First exp. attempts w/ molecules. Dedicated Storage Ring EDM method developed 2000s Proposal for sensitive Deuteron EDM exp. 2010s Proposal for sensitive Proton EDM exp. Important Stages in an EDM Experiment
Polarize: state preparation, intensity of beams Interact with an E-field: the higher the better Analyze: high efficiency analyzer Scientific Interpretation of Result!Easier for the simpler systems Y. Semertzidis, CAPP/IBS, KAIST Yannis Semertzidis, BNL. ICHEP02, 31 July 2002 EDM methods Neutrons: Ultra Cold Neutrons, apply large E-field and a small B-field. Probe frequency shift with E-field flip Atomic & Molecular Systems: Probe 1st order Stark effect Storage Ring EDM for charged particles: Utilize large E-field-Spin precesses out of storage plane (spin vector analysis) Y. Semertzidis, CAPP/IBS, KAIST
EDM method Advances Neutrons: advances in stray B-field effect reduction Atomic & Molecular Systems: high effectiveE-field Storage Ring EDM for D, P: High intensity polarized sources well developed; spin precession techniques in SR well understood Y. Semertzidis, CAPP/IBS, KAIST Y. Semertzidis, CAPP/IBS, KAIST
EDM method Weaknesses Neutrons: Intensity; High sensitivity to strayB-fields: uniformity and gradients; Motional B-fields and geometrical phases Atomic & Molecular Systems: Low intensity of desired states; in some systems: physics interpretation Storage Ring EDM: some systematic errors different from g-2 experiment, large structure Y. Semertzidis, CAPP/IBS, KAIST An electron in an atom 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(Note: Schiff actually said something else) Measuring an EDM of Neutral Particles
H = -(d E+ B) I/I d E B mI = 1/2 2 1 mI = -1/2 d = e cm E = 100 kV/cm w = 10-4 rad/s Neutron EDM experimental limits vs. year Y. Semertzidis, CAPP/IBS, KAIST
Clayton, SNS Y. Semertzidis, CAPP/IBS, KAIST Y. Semertzidis, CAPP/IBS, KAIST
Clayton, SNS Y. Semertzidis, CAPP/IBS, KAIST Applying spin dressing techniques to equalize and further reduce
the stray B-field sensitivity Y. Semertzidis, CAPP/IBS, KAIST
Clayton, SNS Y. Semertzidis, CAPP/IBS, KAIST Y. Semertzidis, CAPP/IBS, KAIST
Clayton, SNS (Lepton Moments, 2014) Y. Semertzidis, CAPP/IBS, KAIST Schedule Feb 2007 Conceptual Design Approved
2009Technical Feasibility, Preliminary Engineering, Cost and Schedule Baseline Approved Aug DOE CD 2/3a Approval Jan Beneficial Occupancy of FnPB UCN Building Oct nEDM Project Completed First Published few ecm 2020nEDM Experiment Completed and Published @ few ecm PSI nEDM, P. Schmidt, Lepton Moments, 2014
The UCN source delivers sufficientstatistics for data taking, potential improvements are being identified The nEDM experiment is taking data, operational reliability has been improved during shutdown 2014 As a test of magnetic field control we have measured the most precise gyromagnetic ratio of mercury-199 and neutron. We expect with 300 data-days until 2016 a statistical sensitivity of 10-26 ecm How about an electron in an atom
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(Note: Schiff actually said something else) Schiff Theorem: A Charged Particle at Equilibrium Feels no Force An electron in a neutral atom feels no force either. However, the average interaction energy is not zero because the EDM in the lab frame is velocity dependent E. Commins et al., Am. J. Phys. 75 (6) 2007 The apparatus and parameter values
B=22 mG V=10 KV, E=~2 MV/m (height of cell ~1cm) SCT = 102 s Y. Semertzidis, CAPP/IBS, KAIST Y. Semertzidis, CAPP/IBS, KAIST
The data The drift in frequency is taken out by taking the frequency difference between the cells. Runs with micro-sparking are taken out. Y. Semertzidis, CAPP/IBS, KAIST The results and best limits
It now dominates the limits on many parameters They expect another improvement factor ~3 - 5. History of 199Hg EDM results
Lamoreaux Jacobs Klipstein Fortson Griffith Swallows Romalis Loftus Fortson Now we will move on to EDM searches (T violation) in which atomic experiments are way out there in a claswswof their own in what they have to tell us about particle physics. Current sensitivity 1987 1993 1995 2001 2009 2014 Y. Semertzidis, CAPP/IBS, KAIST ThO EDM: The ACME team Paul Hess Brendon OLeary Ben Spaun Cris Panda
Jacob Baron Nick Hutzler Elizabeth Petrik Adam West Ivan Kozyryev Max Parsons Emil Kirilov Get new pic with Emil Add photos of all PbO team Amar Vutha Wes Campbell Yulia Gurevich John Doyle Gerald Gabrielse DPD Amplifying the electric field E with a polar molecule
Eext Th+ Small energy splittings in molecules enable polarization P ~ 100% (Eext ~ 1 V/cm enough for ThO) Eeff O Inside molecule, eEDM acted on by Eeff ~ P 2Z 3e/a02 due to relativistic motion P. Sandars 1965 D. DeMille, LM 2014 Eeff 80 GV/cm for ThO* Meyer & Bohn (2008); Skripnikov, Petrov & Titov (2013); Fleig & Nayak (2014) 104(26)84(13)75(2) Requires unpaired electron spin(s) Systematic Error Budget
de x10-30 e-cm Statistical error: 37 D. DeMille, LM 2014 Systematic shifts applied only fromeffects observed to move EDM channel Applied shift small compared to uncertainties Many upgrades planned for ACME signal size
Electrostatic focusing of molecular beam: ~20x (***) Stimulated vs. spontaneous state prep: ~8x (***) Thermochemical beam source~10-50x (**) New fluorescence collection & detectors~4-10x (*) Cycling fluorescence~3-10x (*) Longer integration time~10-100x (***) = fully characterized in auxiliary tests (**) = partially characterized (*) = preliminary observations and/or theory estimates Focusing simulation STIRAP data? Thermochemical beam source data? D. DeMille, LM 2014 >300x gain in N appears feasible ultimately Adam Ritz, LM 2014 Adam Ritz, LM 2014 Adam Ritz, LM 2014 Adam Ritz, LM 2014 Storage Ring Proton EDM
Y. Semertzidis, CAPP/IBS, KAIST Storage Ring Electric Dipole Moment Experiment for the Proton
Revolution in statistics: 1E11 pol. Protons per 1000 s Strong endorsement from P5 under all funding cond. Discussion with DOE-HEP office to plan a successful experiment An experiment to probe proton EDM to 10-29ecm Most sensitive, flavor-conserving CP-violation Complementary to LHC and the neutron EDM; probes New Physics ~1E3 TeV Based on g-2 experience using the magic momentum technique with electric fields The storage ring Proton
Major characteristics of a successful Electric Dipole Moment Experiment Statistical power: High intensity beams Long beam lifetime Long Spin Coherence Time An indirect way to cancel B-field effect A way to cancel geometric-phase effects Control detector systematic errors The storage ring Proton EDM method has it all! Feasibility of an all-electric ring
First all-electric ring (AGS-analog) proposed/built It worked! Two encouraging technical reviews performed at BNL: Dec. 2009, March 2011. Fermilab comprehensive review: Fall Val Lebedev considers the concept to be sound. Cost (2011, 2012 engineering cost): $70M + tunnel. Proton storage ring EDM experiment is combination of beam + a trap Stored beam: The radial E-field force is balanced by the centrifugal force.
Yannis Semertzidis, BNL 44 The proton EDM uses an ALL-ELECTRIC ring: spin is aligned with the momentum vector
at the magic momentum E Momentum vector Spin vector Yannis Semertzidis, BNL 45 Feasibility of an all-electric ring
Two technical reviews have been performed at BNL: Dec 2009, March 2011 Fermilab thorough review. Val Lebedev considers the concept to be sound. First all-electric ring: AGS-analog Ring radius 4.7m Proposed-built It worked! Y. Semertzidis, CAPP/IBS, KAIST The proton EDM ring evaluation Val Lebedev (Fermilab)
Beam intensity 1011 protons limited by IBS ,kV The proton EDM ring Total circumference: 500 m
Straight sections are instrumented with quads, BPMs, polarimeters, injection points, etc, as needed. pEDM polarimeter principle (placed in a straight section in the ring): probing the proton spin components as a function of storage time Micro-Megas detector, MRPC or Si. defining aperture polarimeter target Extraction: lowering the vertical focusing carries EDM signal increases slowly with time carries in-plane (g-2) precession signal International srEDM Network Common R&D
srEDM Coll. pEDM Proposal to DOE HEP, NP SQUID-based BPMs B-field shielding/compensation Precision simulation Systematic error studies E-field tests JEDI (COSY/Jlich) Pre-cursor EDM exp. Polarimeter tests Spin Coherence Time tests Precision simulation Cooling E-field tests What has been accomplished?
Polarimeter systematic errors (with beams at KVI, and stored beams at COSY). Precision beam/spin dynamics tracking. Stable lattice, IBS lifetime: 104 s. Spin coherence time 103 s; role of sextupoles understood (using stored beams at COSY). Feasibility of required electric field strength MV/m, 3cm plate separation (JLab, FNAL) Analytic estimation of electric fringe fields and precision beam/spin dynamics tracking. Stable! (Paper already published or in progress.) Work of Md. A. Mamun and E. Forman
J-Lab E-field work: TiN-coated Aluminum No measureable field emission at 225 kV for gaps > 40 mm, happy at high gradient Bare Al TiN-coated Al the hard coating covers defects Work of Md. A. Mamun and E. Forman Any radial magnetic field sensed by the
Clock-wise (CW) & Counter-Clock-wise Storage Any radial magnetic field sensed by the stored particles will also cause their vertical splitting.Unique feature among EDM experiments Equivalent to p-bar p colliders in Magnetic rings Y. Semertzidis, CAPP/IBS, KAIST 53 Distortion of the closed orbit due to Nth-harmonic of radial B-field
Clockwise beam Y() The N=0 component is a first order effect! Counter-clockwise beam Y. Semertzidis, CAPP/IBS, KAIST Time [s] SQUID gradiometers at KRISS SQUID gradiometers at KRISS
Y. Semertzidis, CAPP/IBS, KAIST Y. Semertzidis, CAPP/IBS, KAIST B-field Shielding Requirements
No need for shielding: In principle, with counter-rotating beams. However: BPMs are located only in straight sections sampling finite. The B-field needs to be less than (10-100nT) everywhere to reduce its effect. We are building a prototype (Selcuk Haciomeroglu, CAPP). Y. Semertzidis, CAPP/IBS, KAIST Peter Fierlinger, Garching/Munich
Y. Semertzidis, CAPP/IBS, KAIST Technically driven pEDM timeline
13 14 15 16 17 18 19 20 21 22 Two years system development One year final ring design Three years beam-line construction and installation Y. Semertzidis, CAPP/IBS, KAIST What makes the pEDM experiment
Magic momentum (MM): high intensity charged beam in an all-electric storage ring High analyzing power: A>50% at the MM Weak vertical focusing in an all-electric ring: SCT allows for 103s beneficial storage; prospects for much longer SCT with mixing (cooling and heating) The beam vertical position tells the average radial B-field; the main systematic error source Geometrical-phase specs: 0.1mm plate alignment. Y. Semertzidis, CAPP/IBS, KAIST The Proton EDM experiment status
Support for the proton EDM: CAPP/IBS, KAIST in Korea, R&D support for SQUID-based BPMs, Prototype polarimeter, Spin Coherence Time (SCT) simulations. COSY/Germany, studies with stored, polarized beams, pre-cursor experiment. After the P5 endorsement DOE-HEP requested a white paper to establish the proton EDM experimental plan. Large ring radius is favored: Lower E-field strength required, Long SCT, nT B-field tolerance in ring.Use of existing ring preferred. Physics strength comparison (Marciano)
System Current limit [ecm] Future goal Neutron equivalent Neutron