Abstract: Measurements of the electron electric dipole moment (EDM) using atoms and molecules set the most stringent constraints on T-symmetry violating new physics beyond the Standard Model. The best upper limit on the electron EDM was recently set by the ACME collaboration: |de|<1.1×10-29 e·cm [1], using a cold beam of thorium monoxide (ThO) molecules. This represents an order of magnitude improvement compared to the previous best results [2, 3]. This talk will focus on new upgrades in the 3rd generation ACME [4] which aim for further suppression of both statistical and systematic uncertainties. These pave the way for another order of magnitude improvement in the electron EDM sensitivity for the upcoming ACME measurement.
References:
[1] ACME Collaboration, Improved limit on the electric dipole moment of the electron, Nature 562 355–360 (2018)
[2] ACME Collaboration, Order of Magnitude Smaller Limit on the Electric Dipole Moment of the Electron, Science 343 269–272. (2014)
[3] W. Cairncross et al., Precision Measurement of the Electron’s Electric Dipole Moment Using Trapped Molecular Ions, Phys. Rev. Lett. 119 153001 (2017)
[4] X. Wu et al., The metastable Q 3Δ2 state of ThO: A new resource for the ACME electron EDM search, New Journal of Physics 22 023013 (2020)