Missions

The Agence Nationale de la Recherche (ANR) is funding a detector project promoted by two laboratories, IJCLab and LPCA, in close collaboration with the ISMA institute in Ukraine. The project is entitled GRAiNITA and features the development of a novel technology in electromagnetic calorimetry, based on small grains of scintillating crystals (produced by ISMA). The scintillation light is captured nearby its production site by wavelength shifting fibres allowing for a fine sampling of the electromagnetic cascade to be obtained. The initial results obtained with a small prototype subjected to cosmic rays and particle test beams at CERN are promising. They show that a stochastic sampling term of order 2%/sqrt(E) can be reached and that a constant term better than the 1% could be achieved. The next step of the project is the development and the construction of a demonstrator of the electromagnetic calorimeter to establish these performances quantitatively. This novel detector is resolutely developed to equip an experiment at the Future Circular Collider project. Another aspect of the project concerns the possibility to use the Pulse Shape Discrimination (PSD) technique to measure event-by-event the electromagnetic fraction of an hadronic shower. The ANR is funding one post-doc position to work for a period of two years primarily on the simulations of these novel detectors.

Activities

The successful candidate will work within the FCCee Clermont team and in close collaboration with the other laboratories of the GRAiNITA consortium. Among the tasks envisaged during this contract, the successful candidate will have the responsibility of developing a detailed simulation of the demonstrator within GEANT4, in view of characterising the demonstrator and optimising its design. He or she will contribute to implement this complete simulation in the simulation framework of a FCCee detector concept. Another task will consist in establishing that PSD can be used with the inorganic crystal under consideration (ZnWO4 to start with) to measure the electromagnetic fraction of a shower initiated by a high-energy hadron, with the objective to improve the energy resolution of jets at FCCee. This task will require again GEANT4 simulations of the detector, including the optical model but necessitates as well to educate the simulation with the scintillating time properties of the particles making the hadronic cascade. The literature is scarce on the subject and low energy test beam data are needed. The successful candidate will contribute to these measurement campaigns. Eventually, depending on the profile of the candidate, physics sensitivity studies at FCCee can complement these two main instrumental activities.

Skills

The successful applicant must have completed a PhD in Particle Physics. Acquaintance with flavour physics is preferred though not mandatory. A former experience in detector developments (in particular scintillating detectors) and with GEANT4 simulations is by contrast mandatory.
Programming: skills in C++, ROOT and python.
Language: fluency in spoken and written English.
Good communication skills and ability to work in a team.

Work Context

The successful candidate will join the Clermont Physics Laboratory (LPCA), a joint CNRS/UCA unit. The LPCA is a laboratory with approximately 150 staff, including physicists, engineers, technicians and administrative personnel, and has two main areas of research: elementary particle physics and observational cosmology on the one hand, and applications in health and the environment on the other. It conducts its experimental fundamental physics research in particular through major international particle physics collaborations at the European particle physics laboratory at CERN. The FCCee group at UCA comprises 3 permanent physicists and as many technical staff.

Constraints and risks

Not applicable