Lead Experimental Particle Physicist

What you'll do

You will lead hands-on research and development activities for the FCC-ee experimental program, focusing on beam-induced backgrounds, machine–detector interface studies, and detector optimisation to achieve the desired systematic uncertainties in precision measurements at the Z pole. The role combines technical leadership with active involvement in simulation, detector development, computing, and experimental validation to advance the design and performance of future FCC detectors.

Your responsibilities

Carry out and supervise research and development activities on the experimental environment of the future FCC electron–positron collider, with emphasis on beam-induced backgrounds (BIB) and their impact on detector performance, via the integration of realistic background conditions into detector simulation and data reconstruction workflows.
Develop scalable workflows and software infrastructure ensuring optimal use of computing resources, to run large-scale and detailed beam-induced background simulations. Interpret the results of these simulations to quantify background sources originating from the accelerator, assess their effects on particle detectors, readout strategies and data quality, and design and study strategies to mitigate these backgrounds in close collaboration with accelerator experts and detector designers.
Develop methods to determine key limiting parameters directly from experimental data, towards enabling high-precision physics measurements at FCC-ee, including the definition of requirements for detector alignment, stability, and calibration needed to reach the targeted measurement precision.
Contribute to the design and development of FCC-ee detector technologies, including hands-on work on prototypes, laboratory measurements and test-beam experiments, fostering collaboration between physicists, engineers, and software specialists.
Present results in internal meetings, international workshops, and scientific conferences, and contribute to scientific publications and technical reports.

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Your profile

Proficiency in particle physics data analysis, detector simulation, and collider experimental environment in e+e- collisions.
Full knowledge of the FCC-ee precision physics programme and its implications on the required detector performance.
Agility with programming languages (python, C++) and HEP software tools (ROOT, GuineaPig, BIB Monte-Carlo codes, …).
Proven experience with supervision and team coordination.
Familiarity in detector design and prototyping, and in machine-detector interface studies.
Large scale computing infrastructures (e.g. Condor and workflow management systems).
Electroweak precision measurements with collider data.
You are asked to provide two reference letters as part of your application.
PhD or equivalent relevant experience in the field of Experimental Particle Physics or a related field.

Your skills

Analysis and interpretation of experimental data.
Analysis and optimisation of detector performance: detector/experiment.
Simulation, design and development of (parts of) detectors.
Knowledge and application of physics reconstruction techniques.
Knowledge and application of statistical and numerical mathematical methods.
Has a structured and organised approach towards work; is able to set priorities and plan tasks with results in mind.
Shares knowledge and expertise freely and willingly with others; coaches others to ensure knowledge transfer.
Delivers presentations in a structured and clear way; adjusts style and content to the audience; responds calmly and confidently to questions.
Assimilates large quantities of information, identifies key issues and formulates conclusions clearly and concisely.
Conveys and instils energy, enthusiasm and ownership of CERN goals.
Spoken and written English, with a commitment to learn French.

Ideal start date: 01/07/2026

Contract duration (in months): 60

Grade range: 6

Benchmark job: 200140 - Applied Physicist

Job flexibility: Hybrid

Team supervision

Global Benefits at CERN

A minimum entry-salary of 9236 Swiss Francs per month (tax free), increasing in line with your years of relevant experience.
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, removal, travel expenses) depending on your individual circumstances.
Possibility to extend your contract up to 8 years + eligibility for indefinite contract tenure.

Let's get you ready

Be sure to meet the eligibility criteria

You are a national of a CERN Member State or Associate Member State. Currently, we cannot consider applications from Pakistani and Lithuanian nationals for positions with a 2026 start date, as the ceiling defined under Article II.5 of the Associate Membership Agreement has been reached.
You have relevant qualifications and professional experience.
If you have previously held a Staff contract at CERN, you will not be eligible for these positions.
Please pay attention to the additional criteria and requirements for this specific position and mentioned above.

You will need these documents to complete your application

Your CV (English or French)
Any document you consider relevant to your application

Your CERNDepartment

The EP department conducts research in experimental particle physics in close collaboration with and supporting the wider scientific community working at CERN. This includes designing and operating experiments, developing and constructing detectors, acquiring and analysing physics data.

Overview of CERN

Discover a world where the impossible is made possible!

At CERN, the European Organization for Nuclear Research, we are pushing the frontiers of science and technology. Our groundbreaking work brings together not only physicists but also a diverse range of professionals from engineering, technical, scientific, and administrative fields. Together, we foster an environment where innovation and collaboration thrive.

Every day, we face exciting new challenges and opportunities to contribute to cutting-edge research that shapes our understanding of the universe. We meet these challenges through the diverse perspectives within our teams, ensuring every contribution is valued and driving our shared sense of inclusion and purpose. Diversity is a core value of CERN since its foundation, and it remains central to our mission and continued success.

If you are ready to be part of a dynamic, inclusive community pushing the boundaries of knowledge, CERN is the place where your curiosity and skills can thrive. Be part of our mission to uncover what lies at the heart of the universe! TAKE PART!

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Still have a doubt ? Here are the most frequently asked questions

What should I expect during my first week at CERN?

Your onboarding at CERN includes a comprehensive induction programme, which starts with an official welcome session at the beginning of each month. In addition, you will receive important information both before and after your arrival to ensure a smooth transition into your new role. This process is designed to help you get acquainted with CERN’s environment, your team, and the tools and systems you’ll be using.
How big would the team be?

The size of the team you'll be working with at CERN depends on the specific role and department. Some teams are small and highly specialized, while others are larger and more interdisciplinary. During the interview process, you'll have the opportunity to learn more about the team structure for the position you are applying for.
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The working languages at CERN are English and French. However, it is not always mandatory to speak both languages to work at CERN. We offer language training to help you acquiring the other language.
What support does CERN provide for relocation?

CERN does not offer direct assistance with relocation. However, depending on your role and specific criteria, you may be eligible for certain benefits such as an installation allowance and coverage of travel expenses to join CERN. These benefits are designed to help ease the transition when relocating to the Geneva area. For more information, please consult the “Salary, Benefits and Support“ page.
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What would my salary be?

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