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Probing the Electron EDM with Cold Molecules
E.A. Hinds
Royal Society Research Professor, Centre for Cold Matter, Imperial College, London, UK.
Friday 11th March 2007, 3.30PM, Lecture Theatre EN101 - Ground Floor of EN (Engineering) Building, Hawthorn.
New elementary particle physics (beyond the standard model) is needed
at the 1 TeV energy scale to understand the origin of mass and to explain
why we see more matter than antimatter in the universe. This same new
physics is expected to give the electron a permanent electric dipole (EDM)
in the range of 10-26 - 10-30 e.cm. Thus the search for an electron EDM
is the search for new particle physics. We are measuring the electron EDM
using a beam of cold YbF. This molecule benefits from a large amplification
of the electric dipole interaction, as do several other heavy, polar molecules
(E.A. Hinds, Physica Scripta T70, 34 (1997)). In our experiment this
amplification factor is roughly a million. The present version of our
experiment has the statistical sensitivity to make a measurement at the
level of a few times 10-28 e.cm. and this is in progress.
In the next version of the experiment, our 600 m/s beam will be decelerated
to increase the coherence time. This, together with several other upgrades
now in preparation, will give a further tenfold improvement in sensitivity.
Ultimately it will be possible to trap YbF molecules, perhaps for several seconds.
The combination of large enhancement factor together with long coherence
time promises to bring the uncertainty in the electron EDM into the 10-30 range.
I will discuss the present status of this programme.
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