The organization
Nikhef is the national institute for subatomic physics in the Netherlands. At Nikhef, approximately 270 physicists and 80 technical staff work together in an open and international scientific environment. Together they perform theoretical and experimental research in the fields of particle and astroparticle physics. Nikhef is a partnership between six major Dutch universities and NWO-I Foundation, the Institutes Organization of the Dutch Research Council (NWO).
Among the research collaborations Nikhef participates in are the ALICE, ATLAS and LHCb experiments at CERN, the KM3NeT neutrino telescope in the Mediterranean, the Virgo gravitational waves interferometer in Pisa, the Xenon-nT dark matter experiment in Gran Sasso, the Pierre Auger cosmic ray observatory in Argentina, and the eEDM research programme in Groningen. There are also scientific groups on Theory, Physics Data Processing and Detector R&D. Nikhef avails over excellently equipped technical departments in mechanics, electronics and computing.
The Nikhef ATLAS group
The Nikhef ATLAS group consists of a total of 15 scientific staff, typically 5 postdocs and 15 PhD students. As a founding member of the ATLAS collaboration, the group has a long-term involvement in detector construction (the semiconductor tracker, barrel muon chambers, readout, alignment, and data acquisition).
For the phase-2 upgrade (2027-2030), we will instrument and commission one of the end-caps of a new all-silicon inner tracking system (ITk) in Amsterdam, commission the High Granularity Timing Detector (HGTD), and develop the new universal readout system (FELIX) for ATLAS detector systems.
The group also has a strong record in track reconstruction, flavour tagging algorithm development as well as physics data analysis, with a focus on Higgs boson physics, top quark physics, and searches for new physics signatures.
The position
After the discovery of the Higgs boson in 2012, one of the crucial future challenges for the LHC is to probe its most enigmatic property, the Higgs potential, which can manifest itself in LHC collisions through the production of Higgs boson pairs. These decays, which are 1000 times more rare than single Higgs production according to the Standard Model have not yet been observed. Observation of two-Higgs production is one the most important milestone for the LHC physics program, and will help constrain our knowledge of the Higgs potential, which has shaped the universe at its time of creation, and may hold strong clues about the existence of new physics beyond the Standard Model.
This postdoc position will focus global optimization of diHiggs measurements. The goal is to perform an end-to-end analysis and optimization of all tunable selection criteria for all two-Higgs decay signatures, including the criteria for object selection. This highly complex many-parameter optimization will be based on a machine-learned surrogate model to make it computationally tractable, and will be cross-validated after optimization with a traditional likelihood model. The goal is to identify high-gain optimization strategies that go beyond what can be achieved with traditional local optimization. Beyond developing strategies that can be applied to directly existing Run-3 analyses,
the projects also connects to studies of future large-scale AI models that can be trained to perform many of the data analysis steps directly from the low-level data (foundation models). This postdoc position is co-supervised by prof. dr. Wouter Verkerke and dr. Sascha Caron. The position is based at Nikhef in Amsterdam, and the candidate is employed by the the NWO-I foundation.
You will be strongly embedded in the Nikhef diHiggs group, comprising a PhD student working on the same goal of end-to-end optimization, a postdoc focusing on ML-based optimization in the individual channels, and a PhD that is being recruited simultaneously focusing on the combined interpretation of Run-3 diHiggs measurements. As part of the Nikhef diHiggs team you will also work with staff and PhD students working on the Run-3 analysis of HH decays to bbbb, bbVV, bbττ and bbγγ final states.
The position offered here are part of a NWO-funded physics program “The potential of the Higgs boson”, with prof. dr. Pamela Ferrari as principal investigator, which will ultimately comprise 7 PhD positions and 2 postdoc positions in the Nikhef ATLAS group in the period 2025-2030 all focused on the Higgs boson potential, complemented by 9 Nikhef staff scientists that offer supervision, networking opportunities and a specialized training program in data analysis techniques and Higgs boson physics.
Requirements
We are looking for postdoctoral candidates with an (almost) completed PhD degree in high-energy physics. The ideal candidate has a strong track record in data analysis, has good software skills, several years of research experience in experimental particle physics, and significant experience with the application of machine learning algorithms in data selection in particle physics.
Offer
The candidate will be employed by the NWO-I foundation for a period of three years and will obtain the status of postdoctoral researcher. The conditions of employment are excellent and include extra months’ salary payment in May and December. The gross monthly salary is dependent on relevant experience (scale 10). The conditions of employment of the NWO-I-foundation can be found at https://www.nwo-i.nl/en/employees/
Application
Qualified applicants are encouraged to apply by filling in the template below. The deadline for applications is November 16th, 2025. Please be prepared to upload a short cover letter, a curriculum vitae and have the email address of at least three referees ready who are willing to send a letter of recommendation on your behalf. A knowledge security check can be part of the selection procedure.
Please indicate in which position you are interested in your cover letter. Interviews with selected candidates are foreseen in the period Dec 8-10. For further information, feel free to contact list co-supervisors for details on the positions, or prof. dr. Wouter Verkerke for general information about the Nikhef ATLAS group.