The University of Oklahoma Funding sources for preliminary research: National Research Council (US)...

The University of Oklahoma

Funding sources for preliminary research:Funding sources for preliminary research:

National Research Council (US)National Research Council (US)

NATO SfP (for field measurement.)NATO SfP (for field measurement.)

OU Office of the Vice PresidentOU Office of the Vice Presidentfor Researchfor Research

Current Funding (as of June 1, 2006)Current Funding (as of June 1, 2006)National Science FoundationNational Science Foundation

Neil Shafer-Ray, The University of Oklahoma

Measuring the Electron’s Electric Dipole Moment usingMeasuring the Electron’s Electric Dipole Moment usingzero-g-factor paramagnetic moleculeszero-g-factor paramagnetic molecules

3rd International Symposium on LEPTON MOMENTS 3rd International Symposium on LEPTON MOMENTS Centerville, Cape Cod, MA Centerville, Cape Cod, MA

Wednesday June 21 2006, 10:30am Wednesday June 21 2006, 10:30am


Stated Goal of my NSF sponsored research: Stated Goal of my NSF sponsored research:

(1)(1) To probe for an e-edm at a competitive (10To probe for an e-edm at a competitive (10-28-28e cm) level.e cm) level.

(2) (2) To provide support for a ~10To provide support for a ~10-32 -32 e cm measuremente cm measurementby the Brookhaven-based by the Brookhaven-based

e-edm collaboratione-edm collaboration


g-factors of the electrong-factors of the electron

GHz/ 39962458.1

)(

B

edmB SEgSBgU

cme1093080.1 11



g = 2.0023193043718(14)Gabrielse, this meeting

gedm = 0.00000000000000000(5)Commins, PRL, 2004

For the electron:

GHz/ 39962458.1

)(

B

edmB SEgSBgU

cme1093080.1 11



For paramagnetic molecules YbF, HgF, PbF, PbO,

GHz/1

cme10/mHz10 27

g

SEg

B

edmB

For an ideal e-edm system, we want term 2 to be much bigger than term 1.

For ground-state PbF, one can work with

GHz/0000001.0 gBSee Shafer-Ray, PRA, 2006

Kozlov, Labzowsky, J Phys B, 1995

)( SEgSBgU edmB

1) boring 2) exciting



SEESEgSBgU edmB

ˆˆ)(

For paramagnetic molecules YbF, HgF, PbF, PbO,

GHz/1

cme10/mHz10 27

g

SEg

B

edmB

For an ideal e-edm system, we want term 2 to be much bigger than term 1.

1) boring 2) exciting

For ground-state PbF, one can work with

GHz/0000001.0 gBSee Shafer-Ray, PRA, 2006

Kozlov, Labzowsky, J Phys B, 1995

3) trouble


PbPb

FF

Sz= 1/2

S=(1/2)1/2

Lz==1

L=1

Both spin and orbitalangular momentuminteract strongly withnuclear axis. |+Sz|= ½.

Spin-orbit interactionfavors L

opposite to S.

Simple vector picture of gSimple vector picture of gzz for X for X11221/21/2 PbF: Molecular frame. PbF: Molecular frame.

)034.0( 012 |||| Gg

GKozlov et al, J Phys B, 1987

Kozlov et al, J Phys B, 1987

)326.0( .4 02

1 Gg

G


Simple vector picture of gSimple vector picture of gzz for X for X11221/21/2 PbF: Lab frame PbF: Lab frame

PbPb

FF

G|| =0.034

G = -0.326

)3/2(21

Gg


PbPb

FF

G|| =0.034

G = -0.326



PbPb

FF

G||=0.034

G = -0.326


E)( ||2

1 Gg


g factor of PbF F=1, |Mg factor of PbF F=1, |MFF|=1, high-field seeking ground state:|=1, high-field seeking ground state:

g-factor can be tuned to zero!

)3/2(21

Gg

)( ||21 Gg


Incoherent combination of|1,1>, |1,0> and |1,-1> states

P() = probabilityof finding the systemIn the state M=F whenquantization axis isin the direction of .Shafer-Ray, Orr-Ewing,Zare, JPC, 1995E

LASER RADIATION

|1,1> + |1,-1>

Graphical Description angular momentum distributionGraphical Description angular momentum distribution


EFFECT OF MAGNETIC FIELDS OR ANe-EDM ON

THE DISTRIBUTION OF ANGULAR MOMENTUM

|1,1> + Exp[i U t /] |1,-1>

B


Problem 1: The Geometric Phase Effect

As a molecule movesin a region for which E is not fixed, a topologicalrotation of the angular momentumalignment occurs.


To really take advantage of g≈0, we would like anexperiment

that occurs at B=0in a very homogeneous E field.

Here is one vision of such an experiment. . .

Problem 2: Many errors are tied to the product g Bapplied. For these errors, there is no advantage to

g small if g Bapplied remains large.

Problem 1: The Geometric Phase Effect


PbF molecular beam source

optical polarization(create M=0 state) high-field region

Raman

-RF p

ump

prob

e +

prob

e -

Schematic of PbF g=0 measurementSchematic of PbF g=0 measurement

LIF or REMPI detection region

(probe M=0 state)


First things first: Production and detection of PbFFirst things first: Production and detection of PbF

Pb / F2 flow reactor: Operational Temperature 1200K


(0,0) band

5.0

4.0

0.0

-2.0

-1.0

-3.0

3.0

2.0

1.0

ener

gy (

eV)

X21/2

A21/2

B21/2

PbF+

3.0 5.0 7.0R(Bohr)

1+1 X1+1 X11221/21/2 →→BB221/21/2 REMPI of PbF REMPI of PbF

OU data, 2005


Observation of an ionization threshold for PbFObservation of an ionization threshold for PbF


R(Bohr)

5.0

4.0

0.0

-2.0

-1.0

-3.0

3.0

2.0

1.0

ener

gy (

eV)

?21/2

PbF+

3.0 5.0 7.0

State selective ionization of PbF+ via 1+1+1 doubly-resonant multi-photonionization.

X21/2

A21/2


optic

al p

olar

izatio

n

(cre

ate

M=0

sta

te) high-field region

Raman

-RF p

ump

prob

e +

prob

e -


(probe M=0 state)

X1 21/2 (F=1)

A 21/2 (F=1)

|M|=1

|M|=1M=0

M=0


optic

al p

olar

izatio

n

(cre

ate

M=0

sta


Raman

-RF p

ump

prob

e +

prob

e -


(probe M=0 state)

M=0400MHz|M|=1


Requirements for large Rabi populationamplitude in Raman pumping

from a state A to a state B

(1) of lasers on resonance.

A B

C

(2) At least 1 state C that couples to both A and B.

(3) A finely tuned ratio of A-C to B-C coupling.


0 20 40 60 80 100 120 140ts0

0.2

0.4

0.6

0.8

1

P

Simulation of RF Raman .02

PM=0

P|M|=1

M=0 |M|=1X1 2

A 2

EDC

k = BRF,effective

^

^ ^

0 20 40 60 80 100 120 140ts0

0.2

0.4

0.6

0.8

1

P

Simulation of RF Raman .20

PM=0

P|M|=1

= 0= /2


optic

al p

olar

izatio

n

(cre

ate

M=0

sta


Raman

-RF p

ump

prob

e +

prob

e -


(probe M=0 state)


optic

al p

olar

izatio

n

(cre

ate

M=0

sta


Raman

-RF p

ump

prob

e +

prob

e -


(probe M=0 state)

PROBE+


PROBE-

QQ

QQpgBedm ..

optic

al p

olar

izatio

n

(cre

ate

M=0

sta


Raman

-RF p

ump

prob

e +

prob

e -


(probe M=0 state)


R(Bohr)

5.0

4.0

0.0

-2.0

-1.0

-3.0

3.0

2.0

1.0

ener

gy (

eV)

?21/2

PbF+

3.0 5.0 7.0

X21/2

A21/2

X23/2

I. Excite X21/2 to X23/2

II A. Excite to A21/2 andobserve blue photons.

II B. Excite to ?21/2 and

observe PbF+ ionscorrelated to e-.

OR

Detection of PbF Detection of PbF


Technical Note Technical Note

/2

0

4214/2

02

)()sin(

))sin1(sin(cos)(

dttSignaltS

NdttSignalQ

4 2 0 2 4EEovoltcm1

0.5

0

0.5

1

RF1

RF2

RF1 fixed to a frequency standard.

RF2=RF1+

40 20 0 20 40EEovoltcm1

0.5

0

0.5

1

tan()

S

S

zero crossing independent of ±M phase


Conclusions

• We have found a system for which the effect of background magnetic fields may be suppressed by seven orders of magnitude.

• We have developed a source of PbF as well as sensitive state selective REMPI of the molecule.

• We are designing a beam machine to take advantage of this new system.


THANKS TO:

Chris McRaven , Sivakumar Poopalasingam,Milinde Rupasinghe

Graduate Students:

Chris Crowe, Dustin Combs, Chris BaresUndergraduate Students:

Professor Emeritus: George Kalbfleisch


The University of OklahomaNeil Shafer-Ray Eric AbrahamGeorge KalbfleischKim MiltonJohn FurneauxChung Kao

Petersburg

Nuclear Physics

Institute

Victor Ezhov

Mikhail Kozlov

University of Latvia

Marcis Auzinsch

BNL

Greg Hall

Trevor Sears

Andrew Sandorfi

Lino Miceli

Mark Baker

Craig Thorn

Mike Lowry

Xiangdong Wang

U Cal Berkeley

Dmitry Budker

Derek Kimball

And thanks to the e-EDM COLLABORATION


First e-edm Collaboration Meeting, February 2005Brookhaven National Laboratory

The University of Oklahoma Funding sources for preliminary research: National Research Council (US)...

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