Missions

The JUNO-IJCLab team, offers a postdoc position for fundamental research in neutrino physics within the JUNO experiment. The team has led the conception and major contributions of the Dual-Calorimetry system, for which two light readout systems are needed, thus originally proposing the so-called “small PMT” system. Today's main activities are focused on the imminent physics programme since data taking is starting — detector commissioning is ongoing. The main focus of the scientific research is high precision neutrino oscillation with JUNO, including the measurement of “Mass Ordering” and the subpercent precision on all other parameters (θ12, δm2 and Δm2). The main strategy is to leverage the additional precision from the novel “dual-calorimetry” technique for both detector calibration and high-precision physics.
The successful candidate will play a key role in analysing JUNO's first data, expected in 2025. Their contributions will include:
a) refining JUNO's energy model, a crucial component of the experiment,
b) optimising the use of Dual Calorimetry to enhance energy reconstruction and detector calibration,
c) developing and improving statistical tools, including the fitter, to enable high-precision and mass ordering measurements.
The research will be conducted within the JUNO international collaboration, supported by the IJCLab and Subatech teams, with frequent research visits to China and other collaborating countries, including partners in Asia and Brazil. The primary objective is to make leading scientific contributions to JUNO's physics program while fostering innovative, high-impact research. The postdoctoral candidate will be required to travel regularly to China, near the JUNO experimental site, for extended periods. One of the expected tasks is to actively support detector calibration operations as part of the Dual-Calorimetry scientific program. This involvement will be particularly intense during the initial data-taking phase (around 1 year), including detector commissioning.

Activités

The successful candidate is expected to take a leading role(s) in the following activities:
• JUNO physics analyses (detector data and simulation) in neutrino oscillation physics for the measurement of Mass Ordering and all other model parameters within JUNO sensitivity.
• JUNO detector running (shifts), commissioning and calibration.
• Experience in event reconstruction, data analysis, and detector simulation (Geant4) is essential. Additional experience in instrumentation is a plus.
• Proficiency in C++ and ROOT is mandatory; experience with Python is highly desirable.
• Development and optimisation of Dual-Calorimetry-based analyses and studies to enhance JUNO's overall precision.
• Participate in the publications write-up (several envisaged).
• Take initiative for other possible physics cases and/or techniques for the ultimate control of the systematics in the JUNO final analysis.
• Take an active role in supervising possible PhD and undergraduate students whenever available.
• Take an active role in the JUNO international collaboration science and collaboration effort.

Compétences

• A PhD level in particle physics or a similar discipline— priority will be given to neutrino specialists.
• Reactor neutrino experience is particularly welcome.
• Proficiency in modern HEP techniques for data analysis (ROOT, etc) and instrumentation are particularly helpful.
• Geant4 simulation skills and knowledge will be advantageous.
• English proficiency is critical (both spoken and written) — international team and context. Chinese language skills will be highly appreciated, but not required.
• International collaboration, communication, and management.
• Problem-solving skills and critical judgment.
• Teamwork spirit and experience, as well as independent thinking.
• Ability to work and think independently, including organisational

Contexte de travail

The Irène Joliot-Curie Physics Laboratory of 2 Infinities (IJCLab) is a UMR under the supervision of the CNRS (IN2P3), the University of Paris-Saclay and the University of Paris, and is located on the campus of the University of Paris-Saclay in Orsay. The campus is located 20 km south of Paris and easily accessible by RER. The staff is made up of nearly 560 permanent (340 engineers, technicians and administrators and 220 researchers and teacher-researchers) and approximately 200 non-permanent, including 120 doctoral students. The research themes of the laboratory are nuclear physics, high energy physics, theoretical physics, astro-particles, astrophysics and cosmology, particle accelerators, energy and the environment and health. IJCLab has very significant technical capacities (around 280 IT) in all the major fields required to design, develop/implement the experimental devices necessary for its scientific activity, as well as the design, development and use of instruments.
The successful candidate will be working within the JUNO-IJCLab team with recognised expertise in the context of fundamental neutrino physics. The JUNO experiment is one of the largest experiments in neutrino oscillation physics with leading sensitivity to several of the neutrino oscillation parameters such as δm2, θ12 and |Δm2| and unique insight to the atmospheric mass ordering (i.e. the sign of ±Δm2). An interesting “shape-only” based cross-check measurement of θ13 is also possible. In addition, given the large size of the detector (20 kilotons), JUNO is considered one of the most sensitive detectors to supernova and geo-neutrinos as well as proton decay. Some sensitivity (under active investigation) to solar and atmospheric neutrinos might be possible, too.
The research proposed here will be conducted within the JUNO international framework at the IJCLab, with frequent visits to China and other collaborating countries in Asia and Europe. The primary objective is to make significant scientific contributions to JUNO's developing scientific agenda and introduce novel pertinent ideas, if feasible. The team focuses on precision measurements of neutrino oscillation parameters and determining neutrino mass ordering within the JUNO collaboration.
This position is funded by the French National Research Agency (ANR) as part of the project “First Per-Mille Precision and 5σ Neutrino Mass Ordering Determination with JUNO.” Coordinated by Subatech in collaboration with IJCLab, this project aims to leverage JUNO's initial data, positioning it at the forefront of:
a) achieving unprecedented precision in neutrino oscillation experiments, reaching first per-mille accuracy while rigorously controlling systematics through innovative experimental techniques,
b) establishing the first robust determination of neutrino mass ordering (NMO),
c) enhancing synergies between neutrino experiments, maximising JUNO's standalone precision, and boosting its discovery potential—ultimately achieving a 5σ significance on NMO.
Extensive studies conducted by our teams, now published, have demonstrated the feasibility of this ambitious physics program. Many advancements stem from the Dual Calorimetry design of the JUNO detector, pioneered by our teams. This breakthrough significantly improves detector systematics control, further enhancing JUNO's potential for major discoveries.

IJCLAB bases its recruitment policy on the promotion of equality, diversity and inclusion. Essential values, they allow the professional development of agents, who are real actors in a collective success, but also the development of the laboratory itself.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

Some of the work will take place in the laboratory work linked to JUNO experimental operations based in China. Long stays in China are foreseen, as well as in other countries, in international collaboration.