Job Description

Your responsibilities

As the LHC transitions into the High Luminosity era (HL-LHC), the CMS experiment is undergoing significant upgrades to its detectors, including the development of the high-granularity calorimeter (HGCAL). With its groundbreaking transverse and longitudinal segmentation, HGCAL enables advanced 5D (x,y,z,E,t) reconstruction of particle showers. Achieving the necessary performance under high pileup and radiation levels requires novel software solutions for both offline and online event reconstruction. The integration of heterogeneous computing architectures—combining traditional CPUs and GPUs—is crucial to accelerating reconstruction algorithms while maintaining or enhancing physics accuracy.

You will join the CMS HGCAL software and reconstruction team to develop and optimize high-performance event-reconstruction algorithms for HGCAL, playing a key role in advancing the experiment’s capabilities.

Key Responsibilities:

• Develop advanced algorithms (e.g., machine learning, graph-based methods) to accelerate and improve the accuracy of hadronic and electromagnetic energy, particle identification, and timing reconstruction.
• Contribute to the design of solutions for online and offline HGCAL event reconstruction, including clusterization and shower reconstruction within the TICL reconstruction framework.
• Integrate these algorithms into the CMS software framework (CMSSW), ensuring compatibility with evolving trigger and offline workflows.
• Coordinate with external collaborators and institute teams to integrate new ideas and ensure that the code is well-documented, maintainable, and aligned with CMS software standards.
• Ensure the implementation of cutting-edge, scalable solutions to handle the high pileup and radiation levels expected at HL-LHC.

This role includes team supervision responsibilities.

Your profile

Skills

Technical Skills:

• Proficiency in C++ and Python. Familiarity with GPU programming (CUDA, Alpaka, SYCL) is a strong advantage.
• Experience with machine learning frameworks (e.g., PyTorch) is a plus.
• Knowledge of CMSSW or large-scale software development in physics experiments is a strong advantage.

Soft Skills:

• Good communication and collaborative spirit to work in a diverse, international team.
• Ability to document results clearly and provide user-friendly instructions.

Eligibility criteria:

• You are a national of a CERN Member or Associate Member State.
• You have a professional background in Physics (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.

Additional Information

Job closing date: 13.03.2025 at 23: 59 hrs CET.

Contract duration: 24 months, with a possible extension up to 36 months maximum.

Working hours: 40 hours per week

Target start date: 01-April-2025

Job reference: EP-CMG-DS-2025-24-GRAP

Field of work: Applied Physics

What we offer

• A monthly stipend ranging between 6287 and 6911 Swiss Francs per month (net of tax).
• Coverage by CERN’s comprehensive health scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
• Depending on your individual circumstances: installation grant; family, child and infant allowances; payment of travel expenses at the beginning and end of contract.
• 30 days of paid leave per year.
• On-the-job and formal training at CERN as well as in-house language courses for English and/or French.

About us

At CERN, the European Organization for Nuclear Research, physicists and engineers are probing the fundamental structure of the universe. Using the world’s largest and most complex scientific instruments, they study the basic constituents of matter – fundamental particles that are made to collide together at close to the speed of light. The process gives physicists clues about how particles interact, and provides insights into the fundamental laws of nature. Find out more on http://home.cern.

We are on a Quest. A Journey into discovery like no other. Bring your expertise to our unique work and develop your knowledge and skills at pace. Join world-class subject matter experts on unique projects, in a Quest for greater knowledge and deeper understanding.

Begin your CERN Quest. Take Part!

Diversity has been an integral part of CERN’s mission since its foundation and is an established value of the Organization. Employing a diverse workforce is central to our success.