Probing the Deuteron EDM at the 10-26e·cm level with a new Experimental Technique

Yannis K. SemertzidisBrookhaven National Lab

EDM Collaboration

CIPANP03NY City, 20-24 May 2003

EdBdtsd

Muon and Deuteron Electric Dipole Moments in Storage Rings

• Revolutionary New Way of Probing EDMs.

EdBdtsd

Muon and Deuteron Electric Dipole Moments in Storage Rings

• Revolutionary New Way of Probing EDMs.

EdBdtsd

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

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.

Deuteron EDM Signal:

• Radial E-Field:

Rd

R

EadaBdc

BcEddtsd

1

,2 aBcaBcER for γ~1

e.g. for ER = 2MV/m, d = 10-26e·cm; ωd = 2.1µrad/s

Deuteron Statistical Error:

NAPETa

Rsd

2

1

Ts: Time the beam is storedA : The left/right asymmetry observed by the polarimeterP : The beam polarizationN : The total number of detected events

Sources of Deuteron Systematic Errors:

• Out of Plane Electric Field

• Tensor Polarization

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, 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.

Parameter Values of a Deuteron EDM Experiment

• Radial E-Field:

ER=2MV/m

• Dipole B-field: B~0.25T; Ring Radius: R~10m

• Deuteron Momentum:

2aBcER

2.0 GeV/c, 0.4 dP

Storage Time Limitations:• 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 Ts~2s

Deuteron Statistical Error:

NAPETa

Rsd

2

1

Ts = 2sER= 2MV/mA = 0.4P = 90%N = 5 108 d/pulse, 20KHz useful rate and 107s

cme10 26 d

Possible Locations for a Deuteron EDM Experiment:

• Brookhaven National Laboratory

• KVI/The Netherlands

• Indiana University Cyclotron Facility

Indiana University Cyclotron Facility

EDM RingCapital Cost: $3-4M

Accumulator

Deuteron EDM to 10-26 e•cm Sensitivity Level

• 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).

(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 6-10 on Neutron.

Possible Improvements:

• Higher ER Fields: 15.5MV/m for 1 inch Aperture

• Longer Storage Time than 2s while Maintaining Polarization

Breakdown vs Gap

Sensitive Deuteron Electric Dipole Moment Search in Storage Rings

• Revolutionary New Way of Probing EDMs

• Exciting Physics Prospects

Summary