Fundamental interaction and nuclear structure studies with atom traps Peter Müller

2 Argonne 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

3 Outline  Atom trapping 101  Selectivity 39 Ar Trace Analysis  Resolution 6,8 He Charge Radius  Control over external degrees of freedom 6 He  correlation  Control over internal degrees of freedom 225 Ra permanent electric dipole moment

4 Spontaneous Scattering Light Force Resonance & Repetition Laser Beam Atom Resonance Requirement  ~ 10 MHz Scattering Rate  Force Laser Frequency f L f L = f A Force  (f L -f A ) 2 +(  /2) 2 1 p  ~1.5 eV/c p a ~75000 eV/c x 1x10 7 /s

5 Doppler Cooling Laser Beam Atom Laser frequency red detuned  = 6 MHz T D = 0.1 mK

6 Magneto-Optical Trap Raab et al., Bell Lab & MIT, 1987

7 Trapping F = -kxCooling F = -av A Trap with Cooling Magnetic Field B(x) f A (x) Zeeman Shift Atom Velocity f L (v) Doppler Shift

8 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

9 Trapped (-able) Elements “Radioactive” Atom Traps World Wide TRIUMF, Vancouver, Canada K, Rb:  correlation, heavy search Fr: parity violation, anapole moments LBNL, Berkeley, USANa:  correlation KVI, Groningen, NetherlandsRa: electric dipole moment Na:  correlation INFN, Legnaro, ItalyFr: parity violation Tohoku University, Sendai, JapanFr: electric dipole moment (#207) USTC, Hefei, ChinaKr-85,81: trace analysis University of Hamburg, GermanyKr-85: trace analysis University of Heidelberg, GermanyAr-39: trace analysis

10 39 Ar Atom Trap Trace Analysis Argon-39 : cosmogenic isotope half-life = 270 years 39 Ar/Ar = 8 x Radio-Argon Dating : 50 – 1000 year range study ocean and groundwater previously with LLC and AMS Dark Matter Searches : LAr detectors (WARP, DEAP/CLEAN) 39 Ar major background search for old / depleted Argon WIMP Argon Programme

11 Atom Trap Trace Analysis III * Kr-85 Trap loading rates 40 Ar: ~ 3 x / s 38 Ar: ~ 2 x 10 9 / s 39 Ar: 1 in ~ 4 hrs “Life of a single atom” 5p[5/2] 3 5s[3/2] 2 Metastable 811 nm

12 39 Ar at Parts-per-quadrillion Atmospheric 39 Ar/Ar = 8x Depleted 39 Ar/Ar < 1x W. Jiang et al., PRL 106, (2011)

13 Atom Trapping of 6 He & 8 He at GANIL Atom Trap Setup 389 nm 1083 nm 6 He 8 source5x10 7 s -1 1x10 5 s -1 Efficiency = 1x10 trap5 s hr -1 Helium Rates Single atom signal One 6 He atom Spectroscopy 389 nm 23S123S1 11S011S0 2 3 P P 2 Trap 1083 nm He level scheme

14 6 He & 8 He RMS Charge Radii 6 He 8 He Field Shift, MHz-1.464(34)-1.026(63) RMS R CH, fm2.072(9)1.961(16) Total Uncertainty0.4 %0.9 % - Statistical0.1 %0.6 % - Trap Systematics0.3 %0.6 % - Mass Systematics0.1 %0.0 % - He-4: 1.681(4) fm0.1 % L.B. Wang et al., PRL 93, (2004) – He-6 P. Mueller et al., PRL 99, (2007) – He-8 + V. L. Ryjkov et al., PRL 101, (2008): He-8 mass + I. Sick PRC 77, (R) (2008): He-4 Charge Radius + A. Ong, J.C. Berengut, V.V. Flambaum, PRC 82, (2010)

15 Beta-Neutrino Correlation in the Decay of 6 He 6 He 6 Li t 1/2 =0.808 sec 100%  E 0 = MeV Johnson et al., Phys. Rev. (1963) Best experimental limit: a = ± Na

16 Beta-Decay Study with Laser Trapped 6 He 6 He trapping rate of 2  10 3 s -1 with 2  trapping efficiency  a/a = 0.1% in ~4 week beam time Simple … atom, nucleus, decay mode Sensitive to tensor couplings 6 He yields: CENPA: ~1  10 9 s -1 with 7 Li(d,   e) 6 5 p  A -> O. Naviliat-Cuncic, Fri., 11:10

17 Electric Dipole Moment (EDM) Violates Both P and T TP EDMSpinEDMSpinEDM 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…

18 EDM measurement on 225 Ra Transverse cooling Oven: 225 Ra Zeeman Slower Magneto-optical Trap (MOT) Optical dipole trap (ODT) EDM measurement Why trap 225 Ra atoms Large enhancement: EDM (Ra) / EDM (Hg) ~ 10 2 – 10 3 Efficient use of the rare 225 Ra atoms High electric field (> 100 kV/cm) Long coherence times (~ 100 s) Negligible “v x E” systematic effect

19 ODT Shuttle 50 cm ~ 30, Ra atoms ~50  K - atoms moved 50 cm - atom lifetime limited by vacuum ~ 10 s

20 EDM Beamline

21 Dipole trap hand off in EDM science chamber Standing wave ODT Shuttle ODT HV Electrodes

22 EDM measurement on 225 Ra Transverse cooling Oven: 225 Ra Zeeman Slower Magneto-optical trap Optical dipole trap EDM measurement Statistical uncertainty: 100 kV/cm 10 s % 10 days  d = 3  e cm Best experimental limit: d( 199 Hg) < 3  e cm Ra / Hg Enhancement factor ~ s days  d = 3  e cm

23 “Radioactive” Atom Traps elaborate, but high precision tool to manipulate radioactive isotopes high selectivity, sensitivity, resolution, and exquisite control of external and internal degrees of freedom (when you really need it)

24 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