Heavy-Ion Physics and Scientific Machine Learning - Postdoctoral Researcher

Join Lawrence Livermore National Laboratory (LLNL) and contribute to impactful research advancing science and technology for U.S. security and global stability. Our mission covers nuclear deterrence, threat preparedness, energy security, and multi-domain defense, fostering a culture of innovation and operational excellence.

About the role

We have an opening for a Postdoctoral Researcher in the Particle Physics Group to contribute to experimental heavy-ion physics, detector development, and scientific machine learning. You will lead data analysis for the sPHENIX experiment at Brookhaven National Laboratory and the ATLAS experiment at CERN, while advancing DOE Office of Science Nuclear Physics (DOE-NP) and Genesis Mission-funded research milestones focused on AI methods for nuclear physics. Research activities include precision measurements of jet quenching, ultra-peripheral collisions, detector performance studies, and developing next-generation machine learning techniques for particle reconstruction and multimodal data analysis. This position may offer a hybrid schedule, blending in-person and virtual presence.

Responsibilities

• Perform physics analyses using data from the ATLAS and sPHENIX experiments to study the quark-gluon plasma, jet quenching, and heavy-ion collisions.
• Participate in detector operations, commissioning, calibration, performance studies, and data quality monitoring within the ATLAS and sPHENIX collaborations.
• Develop reconstruction, simulation, and analysis software using modern C++, Python, ROOT, and HPC/Grid computing resources for processing multi-petabyte experimental datasets.
• Develop and apply state-of-the-art artificial intelligence and scientific machine learning techniques for particle identification, jet reconstruction, and event interpretation.
• Contribute to DOE-NP and Genesis-funded project milestones focused on multimodal learning, detector performance improvements, and scalable AI methods for experimental nuclear physics.
• Present research at collaboration meetings, DOE reviews, workshops, and international conferences.
• Publish results in leading peer-reviewed journals.
• Collaborate with physicists, computer scientists, and applied mathematicians across LLNL and external institutions.
• Perform other duties as assigned.

Requirements

• Ph.D. in Physics, Nuclear Physics, High Energy Physics, or a closely related discipline.
• Demonstrated research experience in experimental nuclear or particle physics.
• Experience analyzing large scientific datasets using ROOT, Python, C++, or similar scientific software frameworks.
• Experience developing scientific software in Linux environments using modern programming practices.
• Experience with statistical analysis and uncertainty quantification.
• Excellent written and verbal communication skills, including publications and scientific presentations.
• Ability to work effectively in large international collaborations.

Skills

• Experience with the ATLAS, sPHENIX, RHIC, LHC, CMS, ALICE, or STAR collider experiments.
• Experience with jet physics, heavy-ion collisions, and detector performance studies.
• Experience in scientific machine learning, deep learning, foundation models, or multimodal AI.
• Experience with GPU programming, high-performance computing, distributed computing, or large-scale workflow management.
• Experience developing reconstruction, simulation, or detector calibration software.
• Familiarity with modern machine learning frameworks such as PyTorch and TensorFlow.

Benefits

• Flexible Benefits Package
• 401(k)
• Relocation Assistance
• Education Reimbursement Program
• Flexible schedules (*depending on project needs)

Pay

$123,048 Annually. This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. An employee’s position within the salary range will be based on several factors including, but not limited to, specific competencies, relevant education, qualifications, certifications, experience, skills, seniority, geographic location, performance, and business or organizational needs.

Additional Information

This is a Postdoctoral appointment with the possibility of extension to a maximum of three years, open to those who have been awarded a PhD at time of hire date. No security clearance is required; however, if your assignment exceeds 179 days cumulatively within a calendar year, you must undergo the Personal Identity Verification process, including an online background investigation and approval of the background check. The 2025 National Defense Authorization Act (NDAA), Section 3112, restricts access for citizens of China, Russia, Iran, and North Korea without dual U.S. citizenship or legal permanent residence. Candidates must comply with these restrictions to qualify for this position.