HEP Physicist - Data Preservation (EP-FCC-2026-37-GRAP)

Are you excited about giving a second life to a vintage but invaluable set of data, which has the potential to significantly enhance the quality of the preparation studies for the next flagship collider at CERN, the Future Circular Collider?

The LEP data@EDM4HEP project aims at migrating the data collected and LEP in the 1990s, and the corresponding Monte Carlo simulated events, to a new common format developed for the next generation of HEP experiments. This would enable the use of the tools under development for the electron-positron collision phase of FCC, to be tested on real data.

At the same time, the FAIRness of the data sample would be enhanced by improving on Accessibility and Interoperability, mitigating the risk of losing access to the data.

We are looking for a motivated particle physicist with software skills to continue the feasibility work prototyped so far using the ALEPH data. You will work as a member of the CERN EP-FCC group, in close contact with the Key4HEP team of the CERN EP-SFT group, the members of the DPHEP collaboration, and international teams at Brown University and MIT.

Your responsibilities:

• Consolidate the extraction chain of the ALEPH data into EDM4hep. This includes ensuring the right data structures are used, possibly proposing/implementing modifications, and optimising the involved applications for performance and easy-of-use.
• Validate the above with a significant set of benchmark analysis, and apply the validated chain to the whole ALEPH data sample, including Monte Carlo simulated data, complemented with adequate documentation and help tools.
• Consolidate wokflows to produce new Monte Carlo events with the legacy ALEPH software, still available through containers and/or VMS, in particular in what concernes the use of recent event generators.
• Investigate ways to apply the same to DELPHI - and possibly OPAL - data. This will require contacts with the relevant DELPHI and OPAL people.
• Support users of the migrated data in their attempts using their feedback to improve the provided data set and tools.
• Present the result to relevant events.
• If needed, supervise students on specific tasks relevant for the project.

Do you have experience in Research?, Do you have a Master's degree?, * Familiarity with HEP data sets and HEP event data models and their use in analysis.

• Familiarity in building data analysis libraries with C++, FORTRAN and Python.
• Familiarity working on large codebase open source projects.
• Familiarity with tools used in HEP analysis or data storage, such ROOT, and the Key4hep ecosystem.

Skills:

• Proficient in Python, C++, Git, CMake.
• Familiar with FORTRAN 77.
• Flexible to learn new tools and techniques to a level adequate to the project needs.

Optional, but considered a plus:

• Familiarity with Key4hep.
• Spoken and written English, with a commitment to learn French.

Eligibility criteria:

• You are a national of a CERN Member or Associate Member State.
• You have a professional background in Computer Science, Physics, or similar (or a related field) and have either:

• a Master's degree with 2 to 6 years of post-graduation professional experience;
• or a PhD with no more than 3 years of post-graduation professional experience.

• You have never had a CERN fellow or graduate contract before.

• A monthly stipend between 6372-7004 Swiss Francs per month (tax free) depending on your degree.
• 30 days of paid leave per year plus 2 weeks annual closure.
• Coverage by CERN's comprehensive health insurance scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
• Family, child and infant monthly allowances depending on your individual circumstances.
• A relocation package (installation grant and travel expenses) depending on your individual circumstances.
• Possibility to extend your contract up to 36 months.
• On-the-job and formal training including language classes.

Imagine taking part in the largest scientific experiment in the world. CERN needs more than physicists and engineers - if you're a student, a graduate, just starting your career or an experienced professional, whatever your field of expertise, CERN could be your next opportunity.