Applied Physicist

Job Posting Organization:
CERN, the European Organization for Nuclear Research, is a leading scientific research institution established to probe the fundamental structure of the universe. It employs physicists and engineers who utilize the world's largest and most complex scientific instruments to study the basic constituents of matter. CERN has been at the forefront of scientific discovery since its inception, employing thousands of staff and collaborating with numerous countries around the globe. The organization is dedicated to advancing knowledge in particle physics and fostering international collaboration in scientific research.

Job Overview:
The position of Applied Physicist at CERN involves leading hands-on research and development activities for the Future Circular Collider - electron-positron (FCC-ee) experimental program. The primary focus will be on beam-induced backgrounds, machine-detector interface studies, and optimizing detectors to achieve the desired systematic uncertainties in precision measurements at the Z pole. This role requires a combination of technical leadership and active participation in simulation, detector development, computing, and experimental validation. The successful candidate will be responsible for advancing the design and performance of future FCC detectors, ensuring that they meet the high standards required for precision measurements in particle physics.

Duties and Responsibilities:
The duties and responsibilities of the Applied Physicist include:

• Carrying out and supervising research and development activities related to the experimental environment of the FCC electron-positron collider, with a specific emphasis on beam-induced backgrounds and their impact on detector performance.
• Integrating realistic background conditions into detector simulation and data reconstruction workflows.
• Developing scalable workflows and software infrastructure to optimize the use of computing resources for large-scale beam-induced background simulations.
• Interpreting simulation results to quantify background sources from the accelerator and assessing their effects on particle detectors, readout strategies, and data quality.
• Collaborating closely with accelerator experts and detector designers to design and implement strategies to mitigate backgrounds.
• Determining key limiting parameters from experimental data to enable high-precision physics measurements, including defining requirements for detector alignment, stability, and calibration.
• Contributing to the design and development of FCC-ee detector technologies, including hands-on work on prototypes, laboratory measurements, and test-beam experiments.
• Presenting results at internal meetings, international workshops, and scientific conferences, and contributing to scientific publications and technical reports.

Required Qualifications:
Candidates must possess a PhD or equivalent relevant experience in Experimental Particle Physics or a related field. Additionally, they should have proficiency in particle physics data analysis, detector simulation, and a thorough understanding of the collider experimental environment in e+e- collisions. Familiarity with the FCC-ee precision physics program and its implications for detector performance is essential. Candidates should also demonstrate agility with programming languages such as Python and C++, as well as experience with HEP software tools like ROOT and Monte-Carlo codes. Proven experience in supervision and team coordination is required, along with familiarity in detector design and prototyping, and machine-detector interface studies.

Educational Background:
A PhD or equivalent relevant experience in Experimental Particle Physics or a closely related field is required for this position. This educational background ensures that candidates have the necessary theoretical knowledge and practical skills to contribute effectively to the research and development activities at CERN.

Experience:
Candidates should have substantial experience in particle physics data analysis, detector simulation, and the collider experimental environment, particularly in e+e- collisions. Experience in supervising teams and coordinating research efforts is mandatory. Familiarity with large-scale computing infrastructures and electroweak precision measurements with collider data will be considered advantageous.

Languages:
Fluency in spoken and written English is mandatory, and candidates are expected to have a commitment to learning French as part of their professional development.

Additional Notes:
This position is offered as a limited duration contract for 5 years, with the possibility of extension up to 8 years and eligibility for an indefinite contract tenure. The job requires a commitment of 40 hours per week, with hybrid work flexibility. Candidates should be prepared to work during nights, Sundays, and official holidays as required by the needs of the organization. The job grade is classified as 6-7, and the reference for this position is EP-FCC-2026-83-LD. CERN offers a competitive, tax-free salary that increases with relevant experience, along with 30 days of paid leave per year, comprehensive health insurance, and various family allowances. A relocation package is also available depending on individual circumstances.