CP-Violation and Baryon Asymmetry in UniverseElectric 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…

0d

+

-

dd

Phenom.: only thecomponent alongthe spin survives...

+

-

A Permanent EDM Violates both T & P Symmetries:

+

-

+

-

+

-T

P

A Permanent EDM Violates both T & P Symmetries:

EdEdH

PEdH

EdEdH

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

T

PBdH BdBdH

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.

The History of Our Universe

)(

)(

)(

3

44

1

ta

taT

taT

m

years 000,300

,When

equal

m

tt

equalt

The History of Our Universe

Nucleosynthesis builds nuclei up to HeIonized gases

Today’s Cold Universe… Matter Everywhere!

No Antimatter. How did it Happen?

2 ee

2 eeK1010

910/ nnB

equaltttT for ,[sec]/K10 2/110

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

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”

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)

199Hg EDM Experiment

Electric Dipole Moments in Storage Rings

e.g. 1T corresponds to 300 MV/m!

Buddt

sd

B

a

edm

Ron McNabb’s Thesis 2003: C.L. 95% cme107.2 19

x

y

z

sβ

aω

edm

m

e Ba

Buc

2

Indirect Muon EDM limit from the g-2 Experiment

a

edm

tan

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 JPARC/Japan, 2003

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

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”

Radial E-field to Cancel 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

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

R

Ea

daBdc

BcEddt

sd

1

,2 aBcaBcER for γ~1

e.g. for ER = 3.5MV/m, d = 10-27e·cm; ωd = 0.4µrad/s

Deuteron Statistical Error (200MeV):

TotcRp

dfTNAPaE

a2

2

15.6

p : 10s. Polarization Lifetime (Coherence Time)A : 0.3. The left/right asymmetry observed by the polarimeterP : 0.55. The beam polarizationNc : 1011d/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

cme105 28 d 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

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

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=115105 θE rad/s• Deuterons β=0.2, γ=1.02, ω= 13105 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 (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)

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 10-8 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 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

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