Applied Physicist for ATLAS Trigger Reconstruction

Job Posting Organization:
CERN, the European Organization for Nuclear Research, is a leading scientific research institution established in 195

• It is headquartered in Geneva, Switzerland, and is known for its groundbreaking work in particle physics. CERN employs over 2,500 staff members and collaborates with thousands of scientists from around the world, representing more than 100 nationalities. The organization operates in multiple countries and is dedicated to pushing the frontiers of science and technology, fostering an environment of innovation and collaboration.

Job Overview:
The position of Applied Physicist for ATLAS Trigger Reconstruction is integral to the Next Generation Trigger programme at CERN. The primary goal of this role is to enhance the ATLAS trigger system by introducing innovative selections that improve the identification of events in challenging regions of the parameter space. This includes focusing on rare Standard Model processes and exotic signatures. The selected candidate will work closely with NextGen doctoral students to develop the trigger menu for the High-Luminosity Large Hadron Collider (HL-LHC) era. The role requires designing new triggering algorithms and strategies, developing tools for HL-LHC trigger menu studies, simulating trigger selections, and ensuring that proposed solutions comply with trigger menu constraints. The position also involves team supervision responsibilities, making it essential for the candidate to have strong leadership and collaboration skills.

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

• Designing new triggering algorithms and strategies that incorporate alternative data flows and machine learning/AI-based approaches.
• Developing tools to support studies related to the HL-LHC trigger menu.
• Simulating trigger selections and estimating trigger rates using both real data and HL-LHC Monte Carlo samples.
• Ensuring that all proposed solutions adhere to the constraints on processing resources and rate limits set by the trigger menu.
• Implementing solutions within the central ATLAS trigger software framework.
• Collaborating closely with experts in the ATLAS trigger and TDAQ upgrade teams.
• Supervising team members and students, providing guidance and support in their research activities.

Required Qualifications:
Candidates must possess a strong background in collider physics, with experience in AI/ML and trigger systems being highly desirable. Strong software skills are essential, along with excellent communication and presentation abilities. The candidate should also have experience supervising students or a willingness to take on such responsibilities. Proficiency in spoken and written English is mandatory, and a commitment to learning French is expected.

Educational Background:
The educational background required for this position includes a PhD in Physics or a related field. Alternatively, candidates with a Master's degree and 2 to 6 years of post-graduation professional experience will also be considered. It is important that candidates have not previously held a CERN fellow or graduate contract.

Experience:
The level of experience required for this position varies based on educational qualifications. Candidates with a Master's degree should have between 2 to 6 years of relevant professional experience, while those with a PhD should have no more than 3 years of post-graduation professional experience. This ensures that the selected candidate has adequate experience to contribute effectively to the project.

Languages:
Fluency in spoken and written English is mandatory for this position. Additionally, candidates should demonstrate a commitment to learning French, which is considered a valuable asset for effective communication within the organization.

Additional Notes:
The contract duration for this position is 24 months, with the possibility of extension up to a maximum of 36 months. The working hours are set at 40 hours per week, and the role is fully onsite. The target start date for this position is October 1, 202

• The position may require work during nights, Sundays, and official holidays, depending on the needs of the organization. The job reference for this position is EP-ATL-OSW-2026-124-GRAP. Compensation includes a monthly stipend ranging from 6,372 to 7,004 Swiss Francs, which is tax-free, along with 30 days of paid leave per year and additional benefits such as health insurance coverage, family allowances, and a relocation package.