Description du sujet de thèse

The search for electric dipole moment (EDM) of particles probes physics beyond the standard model. It is performed worldwide on elementary particles or composite systems (electron, neutron, Hg and so on …). One of the main motivations is the current lack of CP violating mechanisms. These mechanisms are needed to account for the appearance of matter in our Universe [1]. In the early Universe, matter and antimatter should have been equally produced. Today, there is only a tiny amount of antimatter. Why the antimatter disappears from our Universe is not understood. The discovery of an EDM would reveal new hints towards the understanding of this mystery.
The LPC Caen is involved in an experiment at Paul Scherrer Institute (PSI) in Switzerland aiming at measuring the neutron EDM. The experiment is carried out with ultra-cold neutrons at PSI. These neutrons are of great interest since they can be stored for a few minutes in vessels. During their (long) storage, their intrinsic properties, like the EDM, can be studied.
At PSI, a new spectrometer was built and is nearly operational. A sensitivity improvement of one order of magnitude is expected with respect to the best worldwide measurement performed so far. Among several tasks, the LPC Caen was in charge of the development of the neutron detectors and the analysers of the neutron polarisation. The spectrometer commissioning is ongoing and a first data taking period is planned for 2025 and 2026.
The PhD period (2025-2028) is ideal. The two first years will be dedicated to data taking. The candidate will participate to the analysis of the first collected data. Given the current sensitivity achieved today a new limit is expected. Specific topics related to neutron detection and spin analysis will be addressed during the thesis (data blinding, systematic effects and so on). He / she will have to travel to Switzerland (where a long stay of a few months can be foreseen). He / she will also be involved in the maintenance of the detectors and spin analysing system.

Contexte de travail

The successful candidate will be assigned to the team Mesures de Précision à Basse Énergie, within the Laboratoire de Physique Corpusculaire de Caen (LPC Caen - UMR6534).
The LPC Caen, with about 100 staff, is a joint research unit (UMR6534) depending on three supervisory bodies: the CNRS, the University of Caen Normandy (UNICAEN) and the Ecole Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN). It is located on Campus 2 of the University of Caen Normandy (Campus Côte de Nacre) and is part of the research park of ENSICAEN (www.lpc-caen.in2p3.fr/).

Contraintes et risques

Ionizing radiation / travel in France and abroad