Post-doctoral position on experimental neutrino physics within the JUNO experiment

The JUNO (Jiangmen Underground Neutrino Observatory) is a reactor neutrino experiment that will take place in China. JUNO's main goal is the determination of the neutrino mass ordering, along with a precise measurement of the parameters of the mixing matrix. JUNO also has a rich astroparticle physics program. The JUNO Central Detector filling is completing shortly and data taking is expected to start just before the start of this contract. In order to achieve the required precision for the success of the JUNO physics program, it is essential, in addition to an excellent energy resolution in the Central Detector, to be able to reject all backgrounds mimicking the inverse beta decay (IBD) reactions that are used to tag the reactor electron anti-neutrinos reaching the detector. The most important IBD-like background is from cosmogenic isotopes produced by atmospheric muons crossing the detector. Without proper identification this IBD-like background rate is comparable to the expected neutrino rate. In order to successfully identify, veto these events and well characterize the local atmospheric muon flux, the JUNO veto system was designed.

The IPHC group is responsible for the Top Tracker, which is part of JUNO's veto system. The Top Tracker scintillator modules, which were originally built at IPHC for the OPERA experiment, have had their electronics updated, then been retested and installed in the detector in the first half of 2025. The IPHC group is responsible, in particular, for the development of several electronics cards used in this detector, as well as for the development of the calibration, simulation, and reconstruction software. We are now just starting commissioning of the Top Tracker.

The successful candidate is expected to take part initially in the commissioning and calibration work for the Top Tracker and then in the exploitation of its first data. In particular, it is expected the successful candidate to take a leading role to use this initial data from the Top Tracker data to study the cosmogenic isotope production on the Central Detector of JUNO. Once this is well understood a data-driven sample can be created to model the cosmogenic background to be used in analyses from various different topics. The successful candidate is then expected to join or lead an analysis to precisely measure neutrino oscillations using reactor neutrinos, using the constraints obtained previously on the cosmogenic background.

Activities:

• Participate in the end of the commissioning and calibration of the JUNO Top Tracker.

• Implement improvements to the Top Tracker Geometry and Simulation in the JUNO software to create a more realistic detector.

• Study of cosmogenic production in the Central Detector of JUNO.

• Measurement of neutrino oscillation properties using JUNO data.

How to apply:

Please apply directly at https://emploi.cnrs.fr/Offres/CDD/UMR7178-REGSOM-231/Default.aspx?lang=EN

The application must include the following documents:

• Motivation letter.

• Curriculum Vitae.