We have recently launched the new CeNTREX experiment to search for the electric dipole moment (EDM) of the proton. If the proton has an EDM, it will lead to a deformation in the shape of atomic nuclei known as a Schiff moment. CeNTREX will search for the Schiff moment of the 205Tl nucleus inside a TlF (thallium fluoride) molecule. The observable signature of a Schiff moment will be a shift in the NMR frequency of 205Tl nuclei when the molecules are polarized by a strong electric field. The size of the NMR shift is 3-4 orders of magnitude larger than in similar experiments that use atoms instead of molecules, for the same size of the Schiff moment.
The first generation of CeNTREX, now under construction, will use a cryogenic molecular beam of TlF (similar to that used in our ACME electron EDM search) and will perform state preparation and detection using optical cycling (similar to methods developed for our experiments to laser cool and trap SrF molecules). Later generations of CeNTREX aim to laser cool and trap the TlF molecules for increased sensitivity.