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Yannis K. Semertzidis
Brookhaven National Laboratory
Seminar IUCF, 21 May 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
Questions Physicists Ask:
A Permanent EDM Violates both T & P Symmetries:
Spin is the only vector…
0d
Phenom.: only thecomponent alongthe spin survives...
+
-
+
-
dd
A Permanent EDM Violates both T & P Symmetries:
+
-
+
-
+
-T
P
A Permanent EDM Violates both T & P Symmetries:
EdEdH
ˆˆ
PEdH
EdEdH
ˆˆ
EdH
T
Reality Check: Induced EDMs…
EEdH
TOK
PEEdH
OK
Edd
EdH
1st order Stark effect. Forbidden!
EEdH
2nd order Stark effect. Allowed!
Reality Check: MDMs are Allowed…
BdH
BdBdH
ˆˆT
PBdH
BdBdH
ˆˆ
T-Violation CP-ViolationCPT
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 10-18s-1 75/ aaH
• 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.
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
SM Versus SUSY:
One CP-Violating Phase (CKM).SM:
42 CP-Violating Phases!SUSY:
ála Fortson
d
EdBdt
sd
Usual Experimental Method
Small Signal
Compare the Zeeman FrequenciesWhen E-field is Flipped:
dE421 +
-
TNEd
11
Schiff Theorem:A Charged Particle at Equilibrium Feels no Force……An Electron in a Neutral Atom Feels no Force Either:
0int EEE extTot
…Otherwise it Would be Accelerated…
Neutron EDM Limits
0.1
1
10
100
1000
10000
100000
1000000
50 60 70 80 90
Year
10^
-25
e-cm
Neutron EDM Vs Year
Neutron EDM at LANSCEAiming for a Factor of 50
3
Q=CV
S. Lamoreaux at “Lepton Moments”, June 2003
E=5MV/m,T=108s
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:
0intint BEEF extTot
…the net E-field is not zero!
1960 1970 19901980 20102000
10-30
10-28
10-26
10-24
10-22
10-20E
xper
imen
tal L
imit
on
de (
e . c
m)
Electron EDM
Cs
CsXe* Hg
Cs
Tl
Tl??
Tl
Current Atomic EDM Limits
• Paramagnetic Atoms, 205Tl: electron |de| < 1.610-27e·cm (90%CL)
PRL 88, 071805 (2002)
• Diamagnetic Atoms, 199Hg Nucleus: |d(199Hg)| < 2.110-28e·cm (95%CL)
PRL 86, 2505 (2001)
Electric Dipole Moments in Storage Rings
e.g. 1T corresponds to 300 MV/m!
Buddt
sd
Spin Precession in g-2 Ring(Top View)
Bm
eaa
Momentumvector
Spin vector
Spin Precession in g-2 Ring(Top View)
Bm
eaa
Momentumvector
Spin vector
• The Muon Storage Ring: B ≈ 1.45T, Pμ≈3.09 GeV/c
4 Billion e+ with E>2GeV
aa
t
tAeNdtdN
cos1/ 0
B
a edm
Ron McNabb’s Thesis 2003: C.L. 95% cme107.2 19
x
y
z
sβ
aω
edm
m
e Ba
B
2
Indirect Muon EDM limit from the g-2 Experiment
a
edm
tan
Canceling g-2 with a Radial E-field
x
y
z
sβ
B
edm
Eω
aω
edm
m
e
)1
1(
2 c
EaBa
B
c
E
2
B
c
E
m
e
2Eω
Radial E-field to Cancel/Control the g-2 Precession
• Radial E-Field: 2aBcER
The method works well for particles with small anomalous magnetic moment a, e.g. Muons (a = 0.0011), Deuterons (a = -0.143), etc.
c
EaBa
m
ea
1
12
Spin Precession in g-2 Ring(Top View)
Bm
eaa
Momentumvector
Spin vector
Spin Precession in EDM Ring(Top View)
0a
Momentumvector
Spin vector
The muon spin precesses vertically (Side View)
BVdEddt
sd
B
The muon spin precesses vertically (Side View)
BVdEddt
sd
B
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.
Muon EDM Letter of Intent to J-PARC/Japan, 2003
• †Spokesperson
• # Resident Spokesperson
†
†
#
Expected Muon EDM Value from a
)tan( 10 27
cme 10 210
SUSY22
CP
ad
CPiSUSYSUSY
DM
eDD
Dd
Dm
ea
FDDL
,
,2
and ,2
1 where
,2
1
2
1
2
1 5*5
Predictions in Specific Models
The predicted value for the electron is 10 times lessthan the current experimental limit.
50 effect at 10-24 ecm Exp. Sensitivity!
Predictions in Specific Models
Experimental Goal
T. Feng, et al., hep-ph/0305290“Lepton Dipole Moments and Rare Decays in the CP-Violating MSSM with Non-Universal Soft-Supersymmetry Breaking”
g-2 Values
• Electron 0.0016 done
• Muon 0.0016 doing
• Proton 1.8 ------
• Deuteron -0.15 OK!
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:
Rd
RR
Ea
ad
a
aEdBcEd
dt
sd
2
2
1
1
2aBcER
e.g. for ER = 3.5MV/m, d = 10-27e·cm; ωd = 0.3µrad/s
Enhancement of EDM Signalby Canceling the g-2 Precession
• Edm Signal Rate: 0.3rad/s
• With Cancellation: a 0.1 rad/s; Max vertical spin amplitude within 10s: 1rad
• Without Cancellation: a 106 rad/s; Max vertical spin amplitude within 10s: 0.1prad
Nuclear Scattering as Deuteron EDM polarimeter
IDEA:- make thick target defining aperture- scatter into it with thin target
D
L
U
R
R
DΔ
“extraction”target - ribbon
“defining aperture”primary target
detectorsystem
Target could beAr gas (higher Z).
Target “extracts” byCoulomb scattering deuterons onto thickmain target. There’snot enough goodevents here towarrant detectors.
Hole is largecompared tobeam. Every-thing that goesthrough holestays in thering.
Detector is far enoughaway that doughnutillumination is not anacceptance issue:Δ < R.
Ed Stephenson’s
Deuteron Statistical Error (200MeV):
TotcRp
dfTNAPaE
a
18
2
p : 10s. Polarization Lifetime (Coherence Time)A : 0.5 The left/right asymmetry observed by the polarimeterP : 0.55. The beam polarizationNc : 41011d/cycle. The total number of stored particles per cycleTTot: 107s. Total running time per yearf : 0.01 Useful event rate fractionER : 3.5MV/m. Radial electric field
cme102 28 d per year
Sources of Deuteron Systematic Errors:
• Out of Plane Electric Field (Ev)
• Geometrical Phases (2nd Order Effects)
• Tensor Polarization (E.S.: Different Dependence on a …)
• Polarimeter Detector Related Effects
Effect of Vertical Component of E
0)( vv ruBEeF
c
E
u
EBr
vv
c
EB
c
EBB
c
EBcBEE
Bm
eg
zr
zrr
zrrzz
r
**
*
*
0
2
Ec
E
m
eg
c
E
m
eg
22
v
22
• Deuterons β=0.2, γ=1.02, ω=13105 θE rad/s
CW vs CCW
B
B
E EE-Field doesNOT flip sign!
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, ω100105 θE rad/s• Deuterons β=0.2, γ=1.02, ω 10105 θE rad/s• Muons β=0.98, γ=5, ω 2105 θE rad/s
• Other Diagnostics Include Injecting Forward vs Backward Polarized Beams as well as Radially Pol.
Ev 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)
Tilt-meter Measurements at the g-2 Ring with 1nrad Resolution
Systematic Error Symmetries(+) Same as EDM; (-) is opposite
SpinRelated
PolarimeterRelated
Deuteron EDM Ring Lattice
Deuteron EDM Signal is Strong:
• Radial E-field Controls g-2 Precession Rate
• Intense Polarized Deuteron Beams
• Long Spin Coherence Time 10s
• Polarimeters: Large Left/Right Asymmetry
Deuteron EDM Systematics:
• EV: CW vs CCW Injection
• Geometrical Phases: Local Cancellation of g-2 and CW vs CCW Injection
• Preliminary Flattening of Ring to 10-9rad: Beam Dynamics Resonance and Beam Position Monitors. The Spin Itself is Sensitive…
• Detector Related Effects: CW vs CCW Injection, Spin Flip at Injection
• Leakage Current is a Second Order Effect!
Deuteron EDM to 10-27 ecm Sensitivity Level is 100 times better than 199Hg
• T-odd Nuclear Forces: dd =210-22 ξ e·cm with the best limit for ξ<0.5 10-3 coming from the 199Hg EDM limit (Fortson, et al., PRL 2001), i.e. dd < 10-25 e·cm.
(Sushkov, Flambaum, Khriplovich Sov. Phys. JETP, 60, p. 873 (1984) and Khriplovich and Korkin, Nucl. Phys. A665, p. 365 (2000)).
dd = dp + dn (I. Khriplovich)
It Improves the Current Proton EDM Limit by a Factor of ~10,000 and a Factor 60-100 on Neutron.
Deuteron (D) EDM at 310-
27ecm
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)
( ) NND n p Dd d d d
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
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
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
Parameter Values of Muon EDM Experiment
• Radial E-Field:• E=2MV/m
• Dipole B-field: B~0.25T
• Muon Momentum:
• Need NP2=1016 for 10-24e.cm. Muon EDM LOI: (http://www.bnl.gov/edm) to J-PARC, <one year of running.
2aBcE
5 MeV/c,500 P
d(muon) < 710-19
Left-Right
10-20
10-22
10-24
d e.cm
MultiHiggs SUSY
Electro-magnetic
neutron:
electron:
1960 1970 1980 1990 2000 2010 2020 2030
10-28
10-29
Current status of EDMs
d(electron) < 1.6 10-
27
d(neutron) < 6 10-
26
d(proton) < 6 10-23
la Sauer
d(199Hg) < 2.1 10-28
E-field Stability: Major Breakthrough Idea by Neil Shafer-Ray
E-field Stability of Order 10-8 to 10-9
Parameter Values of Muon EDM Experiment
• Radial E-Field:• E=2MV/m• Dipole B-field: B ~ 0.25T , R ~ 10m
• Muon Momentum:
• Need NP2=1016 for 10-24e.cm. Muon EDM LOI: (http://www.bnl.gov/edm) to J-PARC, <one year of running.
• F. Farley et al., hep-ex/0307006
2aBcE
5 MeV/c,500 P
Parameter Values of a Deuteron EDM Experiment
• Radial E-Field:
ER=3.5MV/m
• Dipole B-field: B~0.1-0.5T; Ring Radius: R~15-30m
• Deuteron Momentum:
• YkS et al., hep/ex-0308063
2aBcER
5.0 GeV/c, 1 dP
Deuteron EDM to 10-27 ecm Sensitivity Level is 100 times better than 199Hg
• T-odd Nuclear Forces: dd =210-22 ξ e·cm with the best limit for ξ<0.5 10-3 coming from the 199Hg EDM limit (Fortson, et al., PRL 2001), i.e. dd < 10-25 e·cm.
(Sushkov, Flambaum, Khriplovich Sov. Phys. JETP, 60, p. 873 (1984) and Khriplovich and Korkin, Nucl. Phys. A665, p. 365 (2000)).
dd = dp + dn (I. Khriplovich)
It Improves the Current Proton EDM Limit by a Factor of ~10,000 and a Factor 60-100 on Neutron.
Possible Improvements:
• Higher ER Fields: 14MV/m with gas to slow down free electrons.
• Longer Storage Time than 10s while Maintaining Polarization (Coherence Time).
Deuteron Statistical Error:
TotcRp
dfTNAPaE
a2
2
15.6
p : Polarization Lifetime (Coherence Time)A : The left/right asymmetry observed by the polarimeterP : The beam polarizationNc : The total number of stored particles per cycleTTot: Total running timef : Useful event rate fractionER : Radial electric field
Signal and Background:
Ea
ad
dt
ds2
1
Ecdt
ds E2
