Searching for hints of CP violation in the radioactivity of polarized ions: the MORA project

Why are we living in a world of matter? What is the reason for the large matter–antimatter asymmetry observed in the Universe? The MORA (Matter’s Origin from the RadioActivity of trapped and oriented ions) project aims at searching for possible hints in nuclear beta decays, through the measurement of the so-called D correlation. The MORA project started in 2018 [1]. The D correlation offers the possibility to search for new CP-violating interactions in a region that is less accessible by EDM searches, in particular via the Leptoquark model.

With a sensitivity on D close to 10⁻⁵, the MORA apparatus will additionally permit to probe the FSI (Final State Interactions) effects for the first time. Technically, MORA uses an innovative in-trap orientation method, which combines the high trapping efficiency of a transparent Paul trap with laser orientation techniques. Recent studies have shown that a polarization degree close to 100% could be obtained with ²³Mg⁺ ions in the trap after a few pulses of a laser system based on Ti:Sa cavities. The transparent Paul trap and beam optics have been designed with numerical methods to optimize the trap performances while maintaining large solid angles for the detection of the charged particles emitted during the decay. The tests of the detection setup are progressing. The MORA apparatus will be first commissioned in the IGISOL beam lines at JYFL where the laser system is readily available, before moving back to GANIL where its nominal sensitivity to New Physics will eventually be obtained with the intense beams of SPIRAL 1.

[1]: P. Delahaye et al., arXiv:1812.02970, proceedings of the TCP 2018 conference,  Hyp. Int.(2019)240:63.