The MORA project: a new attempt to explain the matter-antimatter asymmetry observed in the Universe

The team GRIFON (GRoupe Interactions FOndamentales et nature du Neutrino) of LPC Caen proposes a PhD thesis as part of the MORA project (Matter’s Origin from the RadioActivity of trapped and laser oriented ions) which is funded by the Region Normandie and the French research national agency (ANR). The final goal of the project, in collaboration with GANIL, is to find new sources of CP violation that could explain the matter-antimatter asymmetry observed in our Universe. The method considered is the measurement of a triple correlation parameter, D, between particles and ions emitted during the decay of short-lived radioactive elements. The measurement of D requires a polarized radioactive source, well located in space and in vacuum to allow the detection of recoil ions in coincidence with beta particles. A Paul-type ion trap, such as the one developed for LPCTrap (E. Liénard et al., Hyperfine Interactions 236 (2015) 1), is well suited to produce such a source. The polarization of the radioactive nuclei confined in the trap will be achieved by optical pumping using a laser at an appropriate frequency. Such polarization has never been carried out in a 3-dimensional Paul trap, and this is the technical originality of the project. The degree of polarization achieved will be measured for the first time at the JYFL laboratory in Jyväskylä in Finland where the available lasers are adapted to the 23Mg nucleus, a good candidate for the measurement of D. The final measurement of the correlation parameter, with unprecedented precision, will be performed at GANIL where the 23Mg will be produced with higher intensity in a few years.

The PhD candidate will participate in all stages of the project, from the tests of the device at LPC Caen to the measurement of the degree of ion polarization in the trap at JYFL in Finland. The candidate will first focus on testing and qualifying the whole setup and then contribute to the installation of the device in the Finnish laboratory. Contributions to physics simulations using the GEANT4 toolkit could also be considered. Finally, he or she will participate in the first measurements of the degree of polarization of the 23Mg ions confined in the trap, achieved by the optical pumping method. The entire project will be performed in close collaboration with the GANIL team.