Sensitivity improvements to the YbF electron electric dipole moment

The electron is predicted to have a small electric dipole moment (EDM). The Standard Model (SM) predicts the EDM to be too small to ever detect at $d_{e}<10^{-38}$ e.cm. However, many extensions of the SM that suggest additional processes, predict the electron’s EDM to be within a measurable regime of both current and proposed experiments. This poster presents some of the technical improvements made to the YbF electron EDM experiment since the last measurement. We have increased the statistical sensitivity of our interferometer by increasing the number of YbF molecules that participate in the experiment and by increasing their detection probability. We demonstrate several hardware developments that combine laser, microwave and rf fields which, when applied to YbF, can pump six times more population into the initial measurement state. In the detection region we have used techniques developed for molecular laser cooling, including resonant polarisation modulation, to dramatically increase the number of scattered photons by a factor of 10. Including other improvements, the statistical uncertainty of our measurement is expected to be reduced by a factor of 90, allowing us to search for physics beyond the SM and below the recent upper limit of $d_{e}<8.9\times10^{-29}$ e.cm.