Search for a neutron electric dipole moment at PSI

Full text: A non-zero neutron electric dipole moment (nEDM) would violate time reversal symmetry and could help explain the observed baryon asymmetry in the universe. A collaboration of 15 European institutes is currently commissioning an experiment to measure the nEDM at the new ultracold neutron (UCN) source at PSI. In the first stage of a two-stage project we will employ an upgraded version of the apparatus that was used by the RAL/Sussex/ILL collaboration for the measurement that set the current best limit of 2.9 x 10-26 e.cm. By exploiting the high UCN intensity at PSI we expect to achieve a factor of five improvement over the present limit, i.e., attain a sensitivity of 5 x 10-27 e.cm, in about two years of operation. In the next stage, a new apparatus, which is presently under development, will improve the sensitivity limit to a few 10-28 e.cm. (author)