Etude des sections efficaces et des asymétries di-leptoniques à LEP2. Contraintes sur la physique au-delà du Modèle Standard

I describe in this HDR the scientific works that I have done since my PhD, defended in 1994. The first part of these works was devoted to the development of detectors within the BaBar experiment. The second part, more extensively described here, was the study of the di-leptonic events produced in the ALEPH experiment at LEP2. In the BaBar experiment, I initially contributed to the feasibility study of a Cerenkov counter dedicated to the identification of charged particles. I had then the responsibility of the construction of a wire chamber for the monitoring of the gain, installed in the gas distribution system of the BaBar drift chamber. These activities included design and simulation of instruments as well as analysis of tests data. Then, I participated to the LEP2 data analysis by measuring cross-sections and forward-backward asymmetries of the di-leptonic processes. I made the interpretation of these measurements under various scenarios of new physics beyond the Standard Model, such as four fermions contact interactions, extra-dimensions and production of sneutrinos with R-parity violation. Moreover, I participated to the combination of the di-leptonic results from the four LEP experiments. Those years between construction of detectors and data analysis in the field of electroweak physics make me join today the thematic of neutrinos. The research plan that I present here focuses on this thematic, especially on my future involvement in the Laguna-LBNO project. Finally, I describe also here my various scientific outreach activities, especially toward the scholars, because, in addition to my research and teaching, this is a non-negligible part of my activity in the past decade.