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Measurement of the Casimir-Polder force This project uses a magneto-optical trap to study the interactions between atoms and surfaces. We measure the variation in acceleration that the atoms feel (compared to the gravitational acceleration alone) due to the presence of a nearby surface. The interaction at very short distances is dominated by the van der Waals-London force and as the distance to the surface increases it is replaced by the Casimir Polder force. The origin of this last force comes from the vacuum field fluctuations. Measuring this force with high precision will result in the observation of the modification of the force due to thermal field fluctuations, and it will set new constraints in short distance forces of the Yukawa type. |
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Francium spectroscopy for the study of the weak force This project is part of the FrPNC project at TRIUMF in Vancouver, Canada, directed by Gerald Gwinner from the University of Manitoba. Francium is the heaviest of the alkali atoms so it has both a big nucleus and a relatively simple atomic structure. The big nucleus amplifies the effects of the weak force and we use the very sensitive tools of atomic spectroscopy to measure these small effects. We are interested in particular in studying neutral weak currents between nucleons inside the nucleus. The main effect of such interaction is to introduce a parity violating moment called the anapole moment. We observe this violation by detecting a hyperfine transition that is only allowed due to the anapole moment. These measurements will increase our understanding of the weak force inside the nucleus. This project evolved from the work on francium done by the group of Luis Orozco, where we manage to capture large quantities of francium in a magneto-optical trap and studied its atomic structure. For more information see: -E. Gomez, S. Aubin, G. D. Sprouse, L. A. Orozco, D. P. DeMille, “Measurement method for the nuclear anapole moment of laser-trapped alkali-metal atoms,” Phys. Rev. A 75, 033418 (2007) -E. Gomez, L. A. Orozco, G. D. Sprouse, “Spectroscopy with trapped francium; advances and perspectives for weak interaction studies,” Rep. Prog. Phys. 69, 79 (2006). Other members of the collaboration Prof. G. Gwinner, University of Manitoba Prof. L.A. Orozco, Joint Quantum Institute Prof. G.D. Sprouse, Stony Brook University Dr. J.A. Behr, TRIUMF Dr. K.P. Jackson, TRIUMF Dr. M.R. Pearson, TRIUMF Prof. V.V. Flambaum, University of New South Wales Prof. S.A.M. Aubin, College of William and Mary |