Missions

The CNRS LAPP (Laboratoire d'Annecy de Physique des Particules) institute is looking for excellent candidates for two post-doctoral positions to work on the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. The work is funded through the ERC Consolidator Grant DITTO (2023-2028). The goal of the DITTO project is to provide the complete set of differential cross-section measurements for dilepton production (Drell-Yan scattering) covering not only the light lepton channels ev/μv/ee/µµ, but also extremely challenging third generation τv and ττ final states. These high mass Drell-Yan scattering measurements (HMDY) will be used to probe new phenomena at mass scales beyond the reach of direct production at the LHC through the Standard Model effective field theory framework.
Application and selection will be carried out starting from 21 May 2023, until the position is filled. The positions should start on 1st of October 2023 or shortly after.

Activités

The successful candidates are expected to take the leading role in the ATLAS HMDY measurements based on the combined LHC Run 2 (2015-2018) and Run 3 (2022-2025) data sets. The first position will be focused on the improvements of the tau-lepton performance in the physics analysis and trigger environments as well as precision measurements in the HMDY channels containing tau-leptons. The second position will be focused on the corresponding improvements of the electron performance as well as precision measurements in the light lepton HMDY channels. The analyses and lepton performance improvements will be based on the advanced machine-learning techniques to ensure the best possible precision of the dilepton production measurements at high mass. The successful candidates will work with a software engineer dedicated to ensure the portability of the performance improvements implementation to the High Luminosity LHC ATLAS trigger environment (2029+), which will be based on a hybrid architecture (the exact technology to be chosen in mid-2025).

The positions are based at LAPP, with the possibility to travel to CERN regularly (50 km from LAPP). The positions will be initially for a period of two years with a possibility of an extension. Supervision of PhD and Master students is foreseen.

Compétences

Candidates should hold a Ph.D. degree in particle physics, obtained less than 7 years before the starting date of the position.
A strong experience in software development, data analysis and knowledge of statistical techniques for data analysis for high energy physics experiments is required. Experience with analysis of LHC data based on C/C++ and Python, machine learning techniques and tools, expertise programming accelerators (GPUs etc) would be appreciated. Ability to work in a large international collaboration is a must.
Fluency in English, speaking and writing (B2 minimum).
Basic knowledge of French could be useful.

Contexte de travail

LAPP is a laboratory of the Institute of Nuclear Physics and Particle Physics (IN2P3), an institute of the National Center for Scientific Research (CNRS), which coordinates programs in these fields. LAPP is a joint research unit (UMR 5814) of the CNRS and the University of Savoie Mont-Blanc (USMB). More than 150 researchers, teacher-researchers, engineers, technicians, administrators, students and foreign visitors work there. The research carried out at LAPP aims to study the physics of elementary particles and their fundamental interactions, as well as to explore their links with the great structures of the Universe. The work of the LAPP teams aims, among other things, to understand the origin of the mass of particles, to unravel the mystery of dark matter or to determine what happened to the anti-matter present in our universe at the time of the Big Bang.

The location of LAPP, 50km from CERN, and the presence of the theory laboratory LAPTh in the same premises, make the LAPP campus a very attractive research place. LAPP hosts the MUST mid-range data storage and computing center.

The ATLAS group at LAPP is currently involved in direct searches for new phenomena, precision measurements in the Higgs-boson and gauge-boson sectors as well as the upgrade of the Liquid Argon calorimeter electronics and the construction of the new pixel detector for HL-LHC.

Contraintes et risques

Some short trips have to be planned in France and abroad.

Informations complémentaires

Desired experience of 1 to 4 years up to 7 years

Applicants must:
• Apply on the CNRS Job Portal https://emploi.cnrs.fr/Offres.aspx : submit a cover letter explaining their interest in the position and a detailed curriculum vitae (containing a description of their research experience with a list of publications highlighting their personal contributions).
• Have referrals to send at least 2 letters of recommendation directly to
lapp_administration_rh_secretariat@lapp.in2p3.fr (further information can be obtained from this same email address).