IUCF Collaboration members:
Edward J. Stephenson
Astrid Imig, BNL
An electric dipole moment (EDM) on a sub-atomic particle or atom at a level within reach of proposed experiments would violate time reversal invariance and be a clear signal of new physics outside the Standard Model. The Deuteron EDM Collaboration is investigating the possibility to search for and EDM on a charged particle by placing it in a storage ring and observing the precession of its spin due to the electric field induced by its motion (v x B). This produces electric fields in the particle frame that are as much as an order of magnitude larger than what can routinely be achieved in the laboratory. To give the precession time to develop, we propose to incorporate a radial electric field into the ring to adjust the size of the orbit so that, for a given magnetic field, the orbit period and the spin precession period coincide. The deuteron beam polarization direction will start longitunal and move into the vertical plane under the influence of an EDM. The direction of the spin will be continuously monitored by sampling the beam throughout the store and tracking the progress of the EDM-induced component.
The IUCF contribution involves the design, construction, and
calibration of the deuteron polarimeters. For this, new measurements
are required of the influence of spin on deuteron reactions and
scattering from a carbon target. These measurements have been
started at the KVI in Groningen. Using these data to guide the
design, a prototype will be built and tested at the COSY storage
ring in Julich where we can study the interaction between the
polarimeter and the dynamics of the stored beam.