Fundamental interaction andnuclear structure studies withatom traps

Peter Müller

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Argonne Cold Atom TrappersArgonne Cold Atom Trappers

From left to right: Z.-T. Lu, P. Mueller, I. Sulai, K. Bailey, M. Kalita, S.M. Hu,W. Williams, W. Jiang, T.P. O’Connor, J. Singh, R. Parker, M. Dietrich, R. Holt

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Outline

Atom trapping 101

Selectivity39Ar Trace Analysis

Resolution6,8He Charge Radius

Control over external degrees of freedom 6He correlation

Control over internal degrees of freedom 225Ra permanent electric dipole moment

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Spontaneous Scattering Light Force Resonance & Repetition

Laser BeamAtom

Resonance Requirement

~ 10 MHz

Sca

tter

ing

Rat

e

F

orce

Laser Frequency fLfL = fA

Force (fL-fA)2+(/2)2

1

p ~1.5 eV/c pa ~75000 eV/cx 1x107/s

5

Doppler Cooling

Laser BeamAtom

Laser frequency red detuned

1

2B Dk T h

F V

= 6 MHzTD = 0.1 mK

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Magneto-Optical TrapRaab et al., Bell Lab & MIT, 1987

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TrappingTrappingF = -kx

CoolingCoolingF = -av

A Trap with CoolingA Trap with Cooling

Magnetic Field B(x)

fA(x)Zeeman Shift

Atom Velocity

fL(v)Doppler Shift

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Magneto Optical Trap

Pros:• Cooling: Temperature < 1 mK,

high resolution

• Long observation time: 100 ms – 20 s

• Spatial confinement: trap size < 1 mm

single atom sensitivity

• Selectivity via repeated excitation, isotope shifts, HFS

no isotopic / isobaric interference

Cons:• Relatively feeble forces -> moderate trapping efficiencies

• Need “cycling” transition -> not applicable for all elements

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Trapped (-able) ElementsTrapped (-able) Elements

“Radioactive” Atom Traps World Wide

TRIUMF, Vancouver, Canada K, Rb: correlation, heavy searchFr: parity violation, anapole moments

LBNL, Berkeley, USA Na: correlation

KVI, Groningen , Netherlands Ra: electric dipole momentNa: correlation

INFN, Legnaro, Italy Fr: parity violation

Tohoku University, Sendai, Japan Fr: electric dipole moment (#207)

USTC, Hefei, China Kr-85,81: trace analysis

University of Hamburg, Germany Kr-85: trace analysis

University of Heidelberg, Germany Ar-39: trace analysis

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39Ar Atom Trap Trace Analysis

Argon-39 :• cosmogenic isotope• half-life = 270 years• 39Ar/Ar = 8 x 10-16

Radio-Argon Dating : • 50 – 1000 year range• study ocean and groundwater• previously with LLC and AMS

Dark Matter Searches : • LAr detectors

(WARP,

DEAP/CLEAN)• 39Ar major

background• search for

old / depleted

Argon

WIMP Argon Programme

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Atom Trap Trace Analysis III

* Kr-85

Trap loading rates 40Ar: ~ 3 x 1012 / s 38Ar: ~ 2 x 109 / s 39Ar: 1 in ~ 4 hrs

“Life of a single atom”5p[5/2]3

5s[3/2]2 Metastable

811 nm

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39Ar at Parts-per-quadrillion

Atmospheric 39Ar/Ar = 8x10-16 Depleted 39Ar/Ar < 1x10-16

W. Jiang et al., PRL 106, 103001 (2011)

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Atom Trapping of 6He & 8He at GANIL

Atom Trap Setup

389 nm

1083 nm

6He 8He

@ source 5x107 s-1 1x105 s-1

Efficiency = 1x10-7

@ trap 5 s-1 30 hr-1

Helium Rates

0 5 10 15 200.0

0.2

0.4

0.6

0.8

1.0

1.2

Ph

oto

n c

ou

ntr

ate

/ kH

z

Time (s)

Single atom signal

One 6Heatom

Spectroscopy389 nm

23S1

11S0

2 3P2

3 3P2

Trap1083 nm

He level scheme

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6He & 8He RMS Charge Radii

6He 8He

Field Shift, MHz -1.464(34) -1.026(63)

RMS RCH, fm 2.072(9) 1.961(16)

Total Uncertainty 0.4 % 0.9 %

- Statistical 0.1 % 0.6 %

- Trap Systematics 0.3 % 0.6 %

- Mass Systematics 0.1 % 0.0 %

- He-4: 1.681(4) fm 0.1 % 0.1 %

L.B. Wang et al., PRL 93, 142501 (2004) – He-6 P. Mueller et al., PRL 99, 252501 (2007) – He-8

+ V. L. Ryjkov et al., PRL 101, 012501 (2008): He-8 mass+ I. Sick PRC 77, 041302(R) (2008): He-4 Charge Radius+ A. Ong, J.C. Berengut, V.V. Flambaum, PRC 82, 014320 (2010)

1.6 1.8 2.0 2.2 2.4 2.6 2.8

Nuclear Radii, fm

4He rms charge rms matter Experiment Theory

8He

6He

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Beta-Neutrino Correlation in the Decay of 6He

6He

6Li

t1/2=0.808 sec

100%

0+

1+

E0=3.5097 MeV

, 1 cosap

N EE

Johnson et al., Phys. Rev. (1963)

2 2

2 2 0.4%T T

A A

C C

C C

Best experimental limit:

a = - 0.3343 ± 0.0030

-1.0

-0.5

0.0

0.5

1.0

Cor

rela

tion

Coe

f. a

1.00.80.60.40.20.0

T

A

V

S

-50

-40

-30

-20

-10

0

10

20

a(e

xp)

- a

(SM

)

x10

-3

1.00.80.60.40.20.0

Fermi fraction

6He n

21Na

32Ar

38mK

21Na

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Beta-Decay Study with Laser Trapped 6He

6He trapping rate of 2103 s-1

with 210-6 trapping efficiency

a/a = 0.1% in ~4 week beam time

• Simple … atom, nucleus, decay mode• Sensitive to tensor couplings

6He yields:

• CENPA: ~1109 s-1 with 7Li(d,e)6He @ 5 pA

-> O. Naviliat-Cuncic, Fri., 11:10

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Electric Dipole Moment (EDM) Violates Both P and T

+

-

+

-

-

+

T P

EDM Spin EDM Spin EDM Spin

A permanent EDM violates both time-reversal symmetry and parity

Neutron

Diamagnetic Atoms (Hg, Ra)

Paramagnetic Atoms (Tl)Molecules (PbO,YbF)

Quark EDM

Quark Chromo-EDM

Electron EDM

Physics beyond the Standard Model:

SUSY, String…

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EDM measurement on 225Ra

Transversecooling

Oven:225Ra

Zeeman Slower Magneto-optical

Trap (MOT)

Optical dipoletrap (ODT)

EDMmeasurement

Why trap 225Ra atoms• Large enhancement:

EDM (Ra) / EDM (Hg) ~ 102 – 103

• Efficient use of the rare 225Ra atoms• High electric field (> 100 kV/cm)• Long coherence times (~ 100 s)• Negligible “v x E” systematic effect

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ODT Shuttle

50 cm

~ 30,000226Ra atoms

~50 K

- atoms moved 50 cm

- atom lifetime limited by vacuum ~ 10 s

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EDM Beamline

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Dipole trap hand off in EDM science chamber

Standing wave ODT

ShuttleODT

HV Electrodes

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EDM measurement on 225Ra

Transversecooling

Oven:225Ra

Zeeman Slower Magneto-optical

trap

Opticaldipole trap

EDMmeasurement

Statistical uncertainty:

100 kV/cm10 s

104

10%

10 days

d = 3 10-26 e cm

Best experimental limit: d(199Hg) < 3 10-29 e cmRa / Hg Enhancement factor ~ 102 -103

100 s

106

100 days

d = 3 10-28 e cm

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“Radioactive” Atom Traps

elaborate, but high precision tool tomanipulate radioactive isotopes

high selectivity, sensitivity, resolution, andexquisite control of external and internal degrees of freedom

(when you really need it)

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Thank You!

He-8: P. Mueller, K. Bailey, R. J. Holt, R. V. F. Janssens, Z.-T. Lu, T. P. O'Connor, I. Sulai, Physics Division, Argonne National Laboratory, USA, M.-G. Saint Laurent, J.-Ch. Thomas, A.C.C. Villari, J.A. Alcantara-Nunez, R. Alvez-Conde, M. Dubois, C. Eleon, G. Gaubert, N. Lecesne, GANIL, Caen, France, G. W. F. Drake, University of Windsor, Windsor, Canada, L.-B. Wang, Los Alamos National Laboratory, USA

Ar-39: W. Jiang, W. Williams, K. Bailey, T. O’Connor, Z.-T. Lu, P.Mueller Physics Division, Argonne National Laboratory, R. Purtschert, Institute of Physics, University of Bern, N. Sturchio, Department of Earth and Environmental Science, University of Illinois, A. Davis, Department of Geophysical Sciences, University of Chicago, S.M. Hu, B. Sun, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China

Ra-225: Z.-T. Lu, I. Ahmad, K. Bailey, M. Dietrich, R. J. Holt, J. P. Greene, P. Mueller, T. P. O’Connor, R. Parker, J. Singh, I. A. Sulai, W. L. Trimble, Physics Division, Argonne National Laboratory, M. Kalita, W. Korsch, University of Kentucky, Lexington

He-6: P. Mueller, Z.-T. Lu, W. Williams, Physics Division, Argonne National Laboratory, A. Garcia, D. Hertzog, P. Kammel, R.G.H. Robertson, A. Knecht, D. Zumwalt, R. Hong, G. Harper, E.H. Swanson, University of Washington, Seattle, O. Naviliat-Cuncic, Michigan State University, X. Flechard, LPC Caen

www.phy.anl.gov/mep/atta/