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Yannis K. Semertzidis Brookhaven National Laboratory Seminar KVI, 1 July 2004 EDMs: Why are they important? Our Universe: The Symmetry that isn’t EDM Experimental Techniques EDMs in Storage Rings Prospects of the Field EDMs in Storage Rings: Powerful Probes of Physics Beyond the SM and of CP-Violation
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Spin is the only vector… Phenom.: only the component along the spin survives... + - + -
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A Permanent EDM Violates both T & P Symmetries: + - + - + - T P
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P T
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Reality Check: Induced EDMs… T OK P 1 st order Stark effect. Forbidden! 2 nd order Stark effect. Allowed!
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Reality Check: MDMs are Allowed… T P
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T-Violation CP-Violation CPT 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….
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Before 1929: Universe is Static-Eternal Cosmological Constant is Invented to Stabilize it! Dirac Equation 1928: 1.g=2 for Point-like, Spin ½ Particles 2.Negative Energy States Flashback
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Hubble 1929: Universe is Expanding …If the Universe Expands… a Beginning and a BIG BANG! Km/MPa/s or 10 -18 s -1 Discovery of Positron by Anderson: 1933
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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.
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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
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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
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EDM Searches are Excellent Probes of Physics Beyond the SM: One CP-Violating Phase (CKM), Needs loops with all quark families for a non-zero result (Third Order Effect). SM: 42 CP-Violating Phases, Needs one loop for a non-zero result (First Order Effect). SUSY:
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á la Fortson d
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Usual Experimental Method Small Signal Compare the Zeeman Frequencies When E-field is Flipped: + - Carrier Signal
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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…
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Neutron EDM Vs Year
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Neutron EDM at LANSCE Aiming for a Factor of 50
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3
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Q=CV
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S. Lamoreaux at “Lepton Moments”, June 2003 E=5MV/m, T=10 8 s R&D
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Cost of the n-EDM Experiment at LANSCE $10M for the experimental apparatus $9M for the Beamline R&D? Total $19M plus R&D
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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!
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196019701990198020102000 10 - 30 10 -28 10 -26 10 -24 10 -22 10 -20 Experimental Limit on d e (e. cm) Electron EDM Cs Xe* Hg Cs Tl ?? Tl
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Current Atomic EDM Limits Paramagnetic Atoms, 205 Tl: electron |d e | < 1.6 10 -27 e·cm (90%CL) PRL 88, 071805 (2002) Diamagnetic Atoms, 199 Hg Nucleus: |d( 199 Hg)| < 2.1 10 -28 e·cm (95%CL) PRL 86, 2505 (2001)
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Electric Dipole Moments in Storage Rings e.g. 1T corresponds to 300 MV/m!
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The Muon Storage Ring: B ≈ 1.5 T, P μ ≈ 3 GeV/c
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Spin Precession in g-2 Ring (Top View) Momentum vector Spin vector Angle: a / turn
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Energy Spectrum of Detected Positrons Momentum vector Spin vector Momentum vector Spin vector Software Energy Threshold
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4 Billion e + with E>2GeV
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B Ron McNabb’s Thesis 2003: x y z s β Indirect Muon EDM limit from the g-2 Experiment
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Canceling g-2 with a Radial E-field x y z s β B
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Radial E-field to Cancel/Control 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.
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Effect of E-Field to g-2 Precession In a B-Field In an E-Field
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Spin Precession in g-2 Ring (Top View) Momentum vector Spin vector
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Spin Precession in EDM Ring (Top View) Momentum vector Spin vector
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The muon spin precesses vertically (Side View)
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(U-D)/(U+D) vs Time (U-D)/(U+D)
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Statistical Error (Muon Case): : 11 s. Muon Lifetime A : 0.3 Vertical Asymmetry N Tot P 2 : 5 10 16 The beam intensity at J-PARC per year. E R : 2MV/m Radial electric field value per year
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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.
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Muon EDM Letter of Intent to J-PARC/Japan, 2003 † Spokesperson # Resident Spokesperson † † #
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SUSY: EDM, MDM and Transition Moments are in Same Matrix
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Expected Muon EDM Value from a
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Predictions in Specific Models The predicted value for the electron is 10 times less than the current experimental limit. 50 effect at 10 -24 e cm Exp. Sensitivity!
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g-2 Values Electron0.0016done Muon0.0017doing Proton1.8------ Deuteron-0.143OK!
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Deuteron Coherence Time E, B field stability Multipoles of E, B fields Vertical (Pitch) and Horizontal Oscillations Finite Momentum Acceptance ΔP/P At this time we believe we can do p >10s
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Nuclear Scattering as Deuteron EDM polarimeter IDEA: - make thick target defining aperture - scatter into it with thin target D L U R R D Δ “extraction” target - ribbon “defining aperture” primary target detector system Target could be Ar gas (higher Z). Target “extracts” by Coulomb scattering deuterons onto thick main target. There’s not enough good events here to warrant detectors. Hole is large compared to beam. Every- thing that goes through hole stays in the ring. Detector is far enough away that doughnut illumination is not an acceptance issue: Δ < R.
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Deuteron Statistical Error (200MeV): p : 10s. Polarization Lifetime (Coherence Time) A : 0.5 The left/right asymmetry observed by the polarimeter P : 0.55. The beam polarization N c : 4 10 11 d/cycle. The total number of stored particles per cycle T Tot : 10 7 s. Total running time per year f : 0.01 Useful event rate fraction E R : 3.5MV/m. Radial electric field per year
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Deuteron EDM Signal is Strong: Radial E-field Controls g-2 Precession Rate Intense Polarized Deuteron Beams >10 11 /cycle Long Spin Coherence Time >10s Polarimeters: Large Left/Right Asymmetry ~.5
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Deuteron EDM Systematics: E V : CW vs CCW Injection Geometrical Phases: Local Cancellation of g-2 and CW vs CCW Injection Preliminary Flattening of Ring to 10 -9 rad: Beam Dynamics Resonance and Beam Position Monitors. The Spin Itself is Sensitive… Detector Related Effects: CW vs CCW Injection, Spin Flip before Injection Leakage Current is a Second Order Effect!
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Effect of Vertical Component of E Deuterons β=0.2, γ=1.02, ω=13 10 5 θ E rad/s
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Effect of Vertical Component of E Clock Wise and Counter-Clock Wise Injection: Background: Same Sign Signal: Opposite Sign Protons β=0.15, γ=1.01, ω 100 10 5 θ E rad/s Deuterons β=0.2, γ=1.02, ω 10 10 5 θ E rad/s Muons β=0.98, γ=5, ω 2 10 5 θ E rad/s Other Diagnostics Include Injecting Forward vs Backward Polarized Beams as well as Radially Pol.
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Deuteron EDM Ring Lattice =18m
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CW vs CCW B B EE E-Field does NOT flip sign!
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E v Issues: Temporal Changes (CW and CCW every 10s) Changes Correlated with B-Field Reversals (Fabry-Perot Resonator) E-Field Multipoles Couple to Beam Moments (Pickup Electrodes; Beam Moment Manipulation)
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Tilt-meter Measurements at the g-2 Ring with 1nrad Resolution
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Systematic Error Symmetries (+) Same as EDM; (-) is opposite Spin Related Polarimeter Related
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Deuteron EDM to 10 -27 e cm Sensitivity Level is 100 times better than 199 Hg T-odd Nuclear Forces: d d =2 10 -22 ξ e·cm with the best limit for ξ<0.5 10 -3 coming from the 199 Hg EDM limit (Fortson, et al., PRL 2001), i.e. d d < 10 -25 e·cm. (Sushkov, Flambaum, Khriplovich Sov. Phys. JETP, 60, p. 873 (1984) and Khriplovich and Korkin, Nucl. Phys. A665, p. 365 (2000)).
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I. Khriplovich: It Improves the Current Proton EDM Limit by a Factor of ~10,000 and a Factor 60-100 on Neutron.
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Deuteron (D) EDM at 3 10 -27 e cm Relative strength of various EDM limits as a function of left handed down squark mass (O. Lebedev, K. Olive, M. Pospelov and A. Ritz, hep- ph/0402023) See also J. Hisano, and Y. Shimizou, hep-ph/0406091
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Possible Locations for the Deuteron EDM Experiment: Brookhaven National Laboratory Indiana University Cyclotron Facility KVI/The Netherlands Proposal This Year to DOE/NSF… $25-30M
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Intensity Estimate from the 200MeV LINAC at BNL The BNL Optically Pumped Polarized H - Ion Source (OPPIS) can be modified to produce polarized D -. Source output: 1mA (400 s, 6.7 Hz). Linac output (30 MeV) 50 A, 5% efficiency. Booster Input 1.3 10 11 ions/pulse (50 A 400 s); Rep rate up to 6.7 Hz J. Alessi
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Possible Improvements for the Muon and Deuteron EDMs: Higher E R Fields: 8MV/m (Muons) and 14MV/m (Deuterons) with gas to slow down free electrons. 10 Muon Intensities under Study. Longer than 10s Storage Time while Maintaining Deuteron Polarization (Coherence Time) under Study.
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EDMs Questions Physicists Ask:
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Electric Dipole Moment Searches: Exciting Physics, Forefront of SUSY/Beyond SM Search. Revolutionary New Way of Probing EDMs, Muon and Deuteron Cases-Very Exciting. EDM Experiments could Bring a Major Breakthrough in Elementary Particle Physics. Summary
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Parameter Values of Muon EDM Experiment Radial E-Field: E=2MV/m Dipole B-field: B~0.25T Muon Momentum: Need NP 2 =10 16 for 10 -24 e. cm. Muon EDM LOI: (http://www.bnl.gov/edm) to J-PARC, <one year of running.
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Sources of Deuteron Systematic Errors: Out of Plane Electric Field (E v ) Geometrical Phases (2 nd Order Effects) Tensor Polarization (E.S.: Different Dependence on a …) Polarimeter Detector Related Effects
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E-field Stability: Major Breakthrough Idea by Neil Shafer-Ray E-field Stability of Order 10 -8 to 10 -9
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Parameter Values of Muon EDM Experiment Radial E-Field: E=2MV/m Dipole B-field: B ~ 0.25T, R ~ 10m Muon Momentum: Need NP 2 =10 16 for 10 -24 e. cm. Muon EDM LOI: (http://www.bnl.gov/edm) to J-PARC, <one year of running. F. Farley et al., hep-ex/0307006
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Parameter Values of a Deuteron EDM Experiment Radial E-Field: E R =3.5MV/m Dipole B-field: B~0.1-0.5T; Ring Radius: R~15-30m Deuteron Momentum: YkS et al., hep/ex-0308063
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Signal and Background:
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Deuteron (D) EDM at 3 10 -27 e cm Relative strength of various EDM limits as a function of left handed down squark mass (O. Lebedev, K. Olive, M. Pospelov and A. Ritz, hep- ph/0402023)
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Deuteron EDM Signal: Radial E-Field: e.g. for E R = 3.5MV/m, d = 10 -27 e·cm; ω d = 0.3µrad/s
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SM Versus SUSY: One CP-Violating Phase (CKM). SM: 42 CP-Violating Phases! SUSY:
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Enhancement of EDM Signal by Canceling the g-2 Precession Edm Signal Rate: 0.3 rad/s With Cancellation: a 0.1 rad/s; Max vertical spin amplitude within 10s: 1 rad Without Cancellation: a 10 6 rad/s; Max vertical spin amplitude within 10s: 0.1prad
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We are Studying Target and Polarimetry (Deuteron case) E-field Directional/Amplitude Stability Beam and Spin Dynamics
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