Missions

The selected candidate will lead the development and completion of the reconstruction algorithm for Super- and Hyper-Kamiokande. The very first challenge he/she will face will be to integrate the last missing piece of this algorithm: the reconstruction of multi-ring events. In parallel, he/she may also begin testing the current algorithm on Super-Kamiokande calibration data to validate its performance and develop training procedures to increase the algorithm's robustness against systematics. The candidate will also be invited to apply the algorithm to accelerator (T2K-SK) and atmospheric data, with the goal of updating the flagship results of these experiments and obtaining the very first evidence of CP violation in the lepton sector. As part of this effort, the candidate will also develop and test the future algorithm for the Hyper-Kamiokande experiment and will have the opportunity to test it on the very first data expected in 2028.

To achieve this, the candidate will work closely with the ILANCE, LLR, and IPMU teams. He/she will have the opportunity to supervise several students already heavily involved in this development, including the computing (Machine Learning), reconstruction, and oscillation analysis aspects. Depending on his/her interests, the postdoctoral researcher will also be encouraged to take part in phenomenological developments and tests using the neutrino oscillation fitter, such as low-energy leptogenesis, PMNS unitarity, or models of lepton flavor symmetry, in collaboration with students and theorists already working on these topics. If desired, the candidate may also have the unique opportunity to directly participate in the on-site construction of the Hyper-Kamiokande detector in Kamioka.

Activités

- Development of a GNN-based reconstruction algorithm, with a particular focus on identifying multi-ring events.
- Testing of the algorithm on Super-Kamiokande calibration data, as well as accelerator (T2K) and atmospheric (SK) data.
- Participation in the oscillation analysis of Super-Kamiokande and/or T2K.
- Analysis of the first Hyper-Kamiokande data.
- Involvement in the construction of Hyper-Kamiokande detector.
- Presentation of results at collaboration meetings and conferences.
- Publication in peer-reviewed journals.

Compétences

- Education: PhD in experimental particle physics.
- Programming: Proficiency in Python, C++, and ROOT; basic knowledge of Fortran is a plus.
- Languages: Proficient in spoken and written English (minimum level B2).
- Strong communication skills and ability to work effectively in a team.

Given the complexity of the task, this project requires the selected candidate to have strong expertise in neutrino physics and event reconstruction. Significant experience in machine learning will also be highly valued. Additionally, the candidate must demonstrate a high degree of autonomy in physics and research, and be capable of and enthusiastic about supervising students to achieve the ambitious goals of this reconstruction project.

Contexte de travail

ILANCE Laboratory, CNRS-IN2P3 / The University of Tokyo

ILANCE stands for International Laboratory For Astrophysics, Neutrino And Cosmology Experiments. It is a joint laboratory between CNRS and the University of Tokyo, located on the Kashiwa campus of the University of Tokyo. Its main research topics focus on cosmology, dark matter, neutrino and particle physics. In the coming decade, planned experiments in these fields have the potential to revolutionize our understanding of the formation and evolution of the universe, with the active involvement of ILANCE teams.

Our international laboratory offers an exceptional new educational and research environment for French and Japanese PhD students, postdoctoral researchers, and interns. As an on-site laboratory in Japan, ILANCE brings together researchers, students, postdocs, engineers, and technicians from CNRS and Japanese institutions. The laboratory is composed of long-term visiting international scientists as well as Japanese physicists.

The neutrino group, led by Benjamin Quilain, focuses on neutrino oscillation experiments in Japan: T2K, Super-Kamiokande, and Hyper-Kamiokande. The group includes two permanent researchers, one postdoc, and five PhD students with joint positions between ILANCE and the Laboratoire Leprince-Ringuet (UMR7638).

In the context of the proposed project, the group leader is coordinating the Hyper-Kamiokande reconstruction effort as well as the T2K oscillation analysis working groups. The group also collaborates closely with the IPMU group (P. De Perio et al.) and the software engineers from LLR, aiming to build strong leadership in machine learning-based algorithms that are usable, robust, and well-tested ahead of Hyper-Kamiokande's operation.

A trip to France of a few weeks is required once per year. Additional travel to Kamioka and/or Kyoto may also be expected to finalize analyses and/or participate in detector shifts or construction.

Informations complémentaires

The candidate should provide 2 reference letters.