Laser Cooling Experiments with 37K and 19Ne for Weak Interaction Studies

1. Weak-interaction studies: Prospects for laser cooling experiments with 37K and 19Ne Dr. Rohan Glover University of Liege Prof. Thierry Bastin BriX director, University of Liege

2. Institute for atomic and nuclear physics

3. Weak interaction studies with trapped radioactive isotopes • Irregularities in the weak interaction • Only couples to left handed neutrinos • Parity is maximally violated • Origin is unclear • How can we contribute using laser cooling and trapping techniques? νe X+ β- decay of a neutron e- • Precision spectroscopy on a well defined sample • Improve measurements of β-decay correlation parameters Institute for Atomic and Nuclear Physics, University of Liege

4. Physics beyond the Standard Model? General formula for the angular distribution of the β-decay: where, are the four-momenta of the leptons, , is the nuclear polarization of the parent nucleus along, . aβν, b, c, Aβ, Bν and D are all correlation parameters that depend on the fundamental symmetries of the weak interaction. Deviations from the predicted values indicates new physics! Institute for Atomic and Nuclear Physics, University of Liege

5. What can be trapped? • Elements with a strong optical cycling transition: • alkali’s • noble gases • Other elements: • alkaline earth metals • Selected transition metals and rare earth metals • Ag, Cr, Yb, Hg and Er Behr & GwimmerJ. Phys. G: Nucl. Part. Phys. 36 033101 (2009) Institute for Atomic and Nuclear Physics, University of Liege

6. Current β-decay experiments with laser cooled atoms * Values quoted with uncertainties (stat)(syst) aKnechtet al, PRL, 108 122502 (2012) b Vetter et al, PRC, 77 035502 (2008) cMelconianet al, PLB, 649 370 (2007) dGorelovet al, PRL, 94 142501 (2005) e Pitcairn et al, PRC, 79 015501 (2009) ) fFeldbaumet al,PRA, 76 051402 (2007) gTriambaket al, PRL, 109 042301 (2012) hCalapriceet al, PRL, 35 1566 (1975) iCalapriceet al, PR, 184 1117 (1969) jHallinet al, PRL, 52 337 (1984) Institute for Atomic and Nuclear Physics, University of Liege

7. β-decay of the 19Ne isotope Institute for Atomic and Nuclear Physics, University of Liege

8. Experimental considerations neutralizer radioactive ion source thermal radioactive isotopes To measure asymmetry parameters, Aβ, Bν and D the sample must be spin polarised magneto- optical trap MOT for trapping radioactive isotopes of Potassium* *Gorelov, et al, Hyperfine Interactions, 127 373 (2000) Institute for Atomic and Nuclear Physics, University of Liege

9. Spin-polarization: Optical Pumping Institute for Atomic and Nuclear Physics, University of Liege

10. Spin-polarization: Optical Dipole Trap Institute for Atomic and Nuclear Physics, University of Liege

11. What about 19Ne? neutralizer radioactive ion source thermal radioactive isotopes This standard technique will not work for 19Ne! - The ground state is not optically accessible. magneto- optical trap MOT for trapping radioactive isotopes of Potassium* *Gorelov, et al, Hyperfine Interactions, 127 373 (2000) Institute for Atomic and Nuclear Physics, University of Liege

12. Energy level structure of stable 20Ne

13. A MOT of radioactive 8He Turbo- molecular pump neutralizer Atomic beam slower 1S0 He @ mTorr rf-discharge 3S1 He 8He+ beam magneto- optical trap • ...system efficiency for 6He and 8He ~ 10-7 Institute for Atomic and Nuclear Physics, University of Liege

14. Comparison of 37K and 19Ne Institute for Atomic and Nuclear Physics, University of Liege