CP-Violation and Baryon Asymmetry in Universe Electric Dipole Moments of Fundamental Particles Yannis K. Semertzidis Brookhaven National Lab Colloquium Oklahoma University, 25 March 2004 EDMs: Why are they important? Our Universe: The Symmetry that isn’t EDM Experimental Techniques EDMs in Storage Rings Prospects of the Field
A Permanent EDM Violates both T & P Symmetries:
Spin is the only vector… + - Phenom.: only the component along the spin survives
A Permanent EDM Violates both T & P Symmetries: T P
P T
Reality Check: Induced EDMs… T OK P 1 st order Stark effect. Forbidden! 2 nd order Stark effect. Allowed!
Reality Check: MDMs are Allowed… T P
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….
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
Hubble 1929: Universe is Expanding …If the Universe Expands… a Beginning and a BIG BANG! Km/Mpa/s or ~ s -1 Discovery of Positron by Anderson: 1933
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.
The History of Our Universe
Nucleosynthesis builds nuclei up to He Ionized gases Today’s Cold Universe… Matter Everywhere! No Antimatter. How did it Happen?
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
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
SM Versus SUSY: One CP-Violating Phase (CKM). SM: 42 CP-Violating Phases! SUSY:
la Fortson d
Usual Experimental Method Small Signal Compare the Zeeman Frequencies When E-field is Flipped: + -
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…
Neutron EDM Vs Year
Neutron EDM at LANSCE Aiming for a Factor of 50
3
Q=CV
S. Lamoreaux at “Lepton Moments” E=5MV/m, T=10 8 s R&D
Cost of the n-EDM Experiment at LANSCE $10M for the experimental apparatus $9M for the Beamline R&D? Total $19M plus R&D
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!
Experimental Limit on d e (e. cm) Electron EDM Cs Xe* Hg Cs Tl ?? Tl
Current Atomic EDM Limits Paramagnetic Atoms, 205 Tl: electron |d e | < 1.6 e·cm (90%CL) PRL 88, (2002) Diamagnetic Atoms, 199 Hg Nucleus: |d( 199 Hg)| < 2.1 e·cm (95%CL) PRL 86, 2505 (2001)
199 Hg EDM Experiment
Electric Dipole Moments in Storage Rings e.g. 1T corresponds to 300 MV/m!
B Ron McNabb’s Thesis 2003: x y z s β Indirect Muon EDM limit from the g-2 Experiment
Two Major Ideas: Radial E-field to Cancel the g-2 Precession Injecting CW and CCW Sensitivity: e·cm statistical (1 yr, 0.75MW) Sensitivity: e·cm systematic error Muon EDM LOI: ( to J-PARC.
Muon EDM Letter of Intent to JPARC/Japan, 2003
Spin Precession in g-2 Ring (Top View) Momentum vector Spin vector
Spin Precession in EDM Ring (Top View) Momentum vector Spin vector
The muon spin precesses vertically (Side View)
Predictions in Specific Models The predicted value for the electron is 10 times less than the current experimental limit. 50 effect at e cm Exp. Sensitivity!
Predictions in Specific Models Experimental Goal T. Feng, et al., hep-ph/ “Lepton Dipole Moments and Rare Decays in the CP-Violating MSSM with Non-Universal Soft-Supersymmetry Breaking”
Radial E-field to Cancel the g-2 Precession Radial E-Field: The method works well for particles with small anomalous magnetic moment a, e.g. Muons (a = ), Deuterons (a = ), etc.
g-2 Values Electron0.0016done Muon0.0016doing Proton Deuteron-0.15OK!
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
Deuteron EDM Signal: Radial E-Field: for γ~1 e.g. for E R = 3.5MV/m, d = e·cm; ω d = 0.4µrad/s
Deuteron Statistical Error (200MeV): p : 10s. Polarization Lifetime (Coherence Time) A : 0.3. The left/right asymmetry observed by the polarimeter P : The beam polarization N c : 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
Sources of Deuteron Systematic Errors: Out of Plane Electric Field Tensor Polarization (not a Problem-Smaller is Better)
Effect of Vertical Component of E Deuterons β=0.2, γ=1.02, ω=13 10 5 θ E rad/s
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=115 10 5 θ E rad/s Deuterons β=0.2, γ=1.02, ω= 13 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.
Deuteron (D) EDM at 3 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/ )
Possible Locations for a Deuteron EDM Experiment: Brookhaven National Laboratory Indiana University Cyclotron Facility KVI/The Netherlands Proposal This Year… $20-30M
We are Studying Target and Polarimetry (Deuteron case) E-field Directional/Amplitude Stability Beam and Spin Dynamics
E-field Stability: Major Breakthrough Idea by Neil Shafer-Ray E-field Stability of Order to 10 -9
EDMs Questions Physicists Ask:
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 Solve the Long Standing Mystery of Matter Asymmetry in our Universe Summary
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 e. cm. Muon EDM LOI: ( to J-PARC, <one year of running.
d(muon) < 7 Left-Right d e.cm Multi Higgs SUSY Electro- magnetic neutron: electron: Current status of EDMs d(electron) < 1.6 d(neutron) < 6 d(proton) < 6 la Sauer d( 199 Hg) < 2.1
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 e. cm. Muon EDM LOI: ( to J-PARC, <one year of running. F. Farley et al., hep-ex/
Parameter Values of a Deuteron EDM Experiment Radial E-Field: E R =3.5MV/m Dipole B-field: B~ T; Ring Radius: R~15-30m Deuteron Momentum: YkS et al., hep/ex
Deuteron EDM to e cm Sensitivity Level is 100 times better than 199 Hg T-odd Nuclear Forces: d d =2 ξ e·cm with the best limit for ξ<0.5 coming from the 199 Hg EDM limit (Fortson, et al., PRL 2001), i.e. d d < e·cm. (Sushkov, Flambaum, Khriplovich Sov. Phys. JETP, 60, p. 873 (1984) and Khriplovich and Korkin, Nucl. Phys. A665, p. 365 (2000)).
d d = d p + d n (I. Khriplovich) It Improves the Current Proton EDM Limit by a Factor of ~10,000 and a Factor on Neutron.
Possible Improvements: Higher E R Fields: 14MV/m with gas to slow down free electrons. Longer Storage Time than 10s while Maintaining Polarization (Coherence Time).
Deuteron Statistical Error: p : Polarization Lifetime (Coherence Time) A : The left/right asymmetry observed by the polarimeter P : The beam polarization N c : The total number of stored particles per cycle T Tot : Total running time f : Useful event rate fraction E R : Radial electric field