Yannis K. SemertzidisBrookhaven 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

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 T

OK

PEEdH OK

Edd

EdH 1st order Stark effect. Forbidden!

EEdH 2nd order Stark effect. Allowed!

HdE

0E

Reality Check: MDMs are Allowed…

BdH BdBdH

ˆˆ

T

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 Particles2. 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

• 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

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:

ála Fortson

d

EdBdtsd

Usual Experimental Method

Small Signal

Compare the Zeeman FrequenciesWhen E-field is Flipped:

dE421 +

-

TNEd

11

Carrier Signal

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 d

e (e

. cm

)Electron EDM

Cs

CsXe* Hg

CsTl

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!

Buddtsd

• The Muon Storage Ring: B ≈ 1.5 T, Pμ ≈ 3 GeV/c

Spin Precession in g-2 Ring(Top View)

Bmeaa

Momentumvector

Spin vectorAngle: a / turn

Energy Spectrum of Detected Positrons

Momentumvector

Spin vector

Momentumvector

Spin vector

Software Energy Threshold

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

me Ba

Buc

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

me

)1

1( 2 cEaBa

B

cE

2

B

cE

me

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.

01

12

cEaBa

me

a

Effect of E-Field to g-2 Precession

Bame

cEa

me

11

2

In a B-FieldIn an E-Field

Spin Precession in g-2 Ring(Top View)

Bmeaa

Momentumvector

Spin vector

Spin Precession in EDM Ring(Top View)

0a

Momentumvector

Spin vector

The muon spin precesses vertically (Side View)

BVdEddtsd

B

(U-D)/(U+D) vs Time

(U-D

)/(U

+ D)

Statistical Error (Muon Case):

TotRd NAPE

a

2

21

: 11s. Muon LifetimeA : 0.3 Vertical AsymmetryNTot P2: 51016 The beam intensity at J-PARC per year.ER : 2MV/m Radial electric field value

cme10 24 d per year

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

†

†

#

SUSY: EDM, MDM and Transition Moments are in Same Matrix

Expected Muon EDM Value from a

)tan( 10 27

cme 10 2 10

SUSY22

CP

ad

CPiSUSYSUSY

DM

eDD

Dd

Dmea

FDDL

,

,2

and ,21 where

,2

12

121 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!

g-2 Values• Electron 0.0016 done

• Muon 0.0017 doing

• Proton 1.8 ------

• Deuteron -0.143 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

Nuclear Scattering as Deuteron EDM polarimeter

IDEA:- make thick target defining aperture- scatter into it with thin target

D

L

U

R

RD

Δ

“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.

Deuteron Statistical Error (200MeV):

TotcRpd fTNAPaE

a

1

82

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

Deuteron EDM Signal is Strong:

• Radial E-field Controls g-2 Precession Rate

• Intense Polarized Deuteron Beams >1011/cycle

• Long Spin Coherence Time >10s

• Polarimeters: Large Left/Right Asymmetry ~.5

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 before Injection

• Leakage Current is a Second Order Effect!

Effect of Vertical Component of E0)( vv ruBEeF

cE

uEBr

vv

cEB

cEBB

cEBcBEE

Bmeg

zr

zrr

zrrzz

r

**

*

*

0

2

EcE

meg

cE

meg

22

v

22

• Deuterons β=0.2, γ=1.02, ω=13105 θE 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, 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.

Deuteron EDM Ring Lattice

<R>=18m

CW vs CCW

B

BE EE-Field does

NOT flip sign!

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 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)).

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

See also J. Hisano, and Y. Shimizou, hep-ph/0406091

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

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) 50A, 5% efficiency.

• Booster Input 1.31011 ions/pulse (50A 400s); Rep rate up to 6.7 Hz

J. Alessi

Possible Improvements for the Muon and Deuteron EDMs:

• Higher ER 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.

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 Bring a Major Breakthrough in Elementary Particle Physics.

Summary

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

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

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

Signal and Background:

Ea

addtds

2

1

Ecdt

ds E2

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

Deuteron EDM Signal:

• Radial E-Field:

Rd

RR

Ea

ad

aaEdBcEd

dtsd

2

2

1

1

2aBcER

e.g. for ER = 3.5MV/m, d = 10-27e·cm; ωd = 0.3µrad/s

SM Versus SUSY:

One CP-Violating Phase (CKM).SM:

42 CP-Violating Phases!SUSY:

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

We are Studying

• Target and Polarimetry (Deuteron case)

• E-field Directional/Amplitude Stability

• Beam and Spin Dynamics