Postdoctoral position with the LHCb experiment at CPPM Marseille (M/F)

Job Description

Missions

The LHCb group of the Centre de Physique des Particules de Marseille (CPPM) and Aix-Marseille University (AMU) invites applications for a postdoctoral researcher position on the topics of semileptonic B meson decays and heterogeneous real-time selection software at LHCb.

The LHCb experiment at the LHC proton-proton collider at CERN is dedicated to studies of heavy flavour physics, with the major goal to find deviations from the Standard Model of particle physics in decays of heavy hadrons. The experiment underwent a major upgrade for Run 3 of the LHC (2022-2026) and is planning a second major upgrade (“Upgrade 2”) for Run 5 of the LHC (around 2030).
The unprecedented Run 3 data sample will be the basis of the analysis, while the developments on the heterogeneous real-time selection software are R&D in view of Upgrade 2.

Activity

Over the last years, deviations from Lepton Flavour Universality have appeared in b-hadron decays, such as in the ratios of branching fractions in b → clν transitions. Though no single measurement constitutes an observation, together they point to a pattern of effects beyond the Standard Model.
You will play a leading role in analyzing B → D* l ν decays with electrons in the final state. To this end, you will employ a multidimentional fit, modeling background processes with templates from simulation and control samples in data. A good understanding of the many background processes and of the data-simulation agreement is crucial for this type of analysis, which will be studied with data control samples as well.

The measurement is enabled by LHCb's new real-time selection system fully implemented in software. It uses graphics processing units (GPUs) for the first reconstruction and inclusive selection stage and CPU servers for a refined reconstruction and exclusive selections. In preparation of Upgrade 2, where a data rate five times larger than in Run 3 will have to be processed, the existing framework needs to be enhanced to allow also the second selection stage to be processed on GPUs. You will be an active player in preparing the heterogeneous system for the next upgrade. This will require the usage of modern computing techniques, such as programming for GPU architecture and developments within a heterogeneous software framework.

Your Profil

Skills

Applicants must hold, or are about to obtain, a PhD degree in physics. Excellent knowledge of particle physics, mathematical methods of data analysis, and modern software development skills (python, C++, gitlab CI/CD) are required.

Your Work Environment

Situated at the heart of the "Calanques National Park", on Luminy campus, CPPM is a joint research laboratory between CNRS and Aix-Marseille University with a staff of around 180 researchers, engineers and PhD students. The laboratory studies topics ranging from particle physics, astroparticle physics and cosmology, with a strong technological force in electronics, mechanics, instrumentation and IT, enabling the design and construction of state-of-the-art detector systems, often required to operate under extreme conditions: deep under the sea, in space or underground. Most of our research is carried out within leading international scientific collaborations and our contributions are recognized worldwide. CPPM is committed to ethical research and to diversity and inclusion in the workplace, and provides administrative and logistics support for newcomers (more details here: https://www.cppm.in2p3.fr/web/en/index.html).
The LHCb group at CPPM is actively involved in studies of semileptonic and rare B decays, and leads major projects in the development of the data acquisition system

Constraints and risks

As successful candidate you will travel to CERN regularly and attend national and international workshops and conferences.

Compensation and benefits

Compensation

between 3131,32 et 4341.70 € gross monthly depending of experience

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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