Nikhef is the national institute for subatomic physics in the Netherlands. At Nikhef, approximately 220 physicists and 75 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 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.

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. 

Position 1 will focus on two-Higgs production its most abundant decay mode, to four b-quark jets, with additional emphasis on the reconstruction of highly energetic Higgs bosons, in the so-called boosted regime. Here, special reconstructions are required, as pairs of jets will merge into a single detector objects with substructure.

This position is co-supervised by dr. Frank Filthaut, prof. dr. Tristan du Pree, and prof. dr. Pamela Ferrari. The candidates is employed by NWO institute Nikhef, with the PhD degree granted by the Radboud University

Position 2 will focus two-Higgs production to a pair of b-quark jets and and a pair of tau leptons. While less abundant, the cleaner signature of the tau leptons, strongly reduces the background making it one of the most competitive modes in the current state of the art, and this project aims to further reduce this background with advanced machine learning techniques. This position is co-supervised by dr. Flavia de Almeida Dias, dr. Pamela Ferrari and prof. dr. Ivo van Vulpen. The candidate is employed and granted the PhD degree by the University of Amsterdam.

Position 3 will focus on three-Higgs production to six b-quark jets, with additional emphasis on the calibration and tuning of the flavor tagging algorithms to identify the b-quark jets. Three-Higgs production is sensitive to both the trilinear and quartic self-coupling of the Higgs boson, making it the only experimental probe at the LHC to probe the quartic coupling. This position is co-supervised by prof. dr. Tristan du Pree, dr. Frank Filthaut and prof. dr. Nicolo de Groot. The candidate is employed by NWO institute Nikhef, with the PhD degree granted by the University of Twente.

The positions offered here are part of a NWO-funded physics program “The potential of the Higgs boson”, 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.

 

We are looking for PhD candidates with an (almost) completed Master degree in high-energy physics or in a closely related field. The ideal candidate has a strong interest in data analysis, has good software skills (Python, C++, ROOT) and has (some) research experience in experimental particle physics. Experience with machine learning algorithms and software is desirable but not required.

A temporary fulltime contract for the duration of 4 years (the initial contract will be for a period of 18 months and after satisfactory evaluation it will be extended for a total duration of 4 years). This should lead to a dissertation (PhD thesis). We will draft an educational plan that includes attendance of courses and (international) meetings. We also expect you to assist in teaching undergraduates and master students. During the doctoral program there is the possibility for extended stays at CERN, up to a total of 1 year.  

You will be employed at either the NWO-I-foundation or the University of Amsterdam, depending on the position. The gross monthly salary, based on 38 hours per week and dependent on relevant experience, ranges between €2,901 and €3,707 (scale P), when employed by the University of Amsterdam, or € 2,968 to € 3,801 gross per month when employed by NWO-I. The salary is based on a full-time contract. On top of the monthly salary, excellent secondary benefits apply, such as a 8% holiday allowance in May, and a 8.3% year-end allowance in December and an excellent pension plan. The conditions of employment of the NWO-I-foundation and the University of Amsterdam are comparable. Further details can be found on www.nwo-i.nl and here, respectively.

Qualified applicants are encouraged to apply visiting this link. The deadline for applications is April 18th, 2025. Please be prepared to upload a short cover letter, a curriculum vitae and have the email address of at least two 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(s) you are interested in your cover letter. Interviews with selected candidates are foreseen in the week of May 12th. 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.

The Faculty of Science has a student body of around 8,000, as well as 1,800 members of staff working in education, research or support services. Researchers and students at the Faculty of Science are fascinated by every aspect of how the world works, be it elementary particles, the birth of the universe or the functioning of the brain. The Institute of Physics (IoP) is located in the centre of the Amsterdam Science Park. The IoP – as part of the Faculty of Science – is housed in a modern building with excellent labs and technical facilities. Surrounded by several national research institutes and with our partners at the Vrije Universiteit Amsterdam, the institute is part of a strong physics centre of international standing. One of the institutes that the IoP has very close ties to is Nikhef, the national institute for subatomic physics in The Netherlands. The present vacancy is fully embedded in the ATLAS group of Nikhef.

Radboud University, based in Nijmegen, hosts approximately 24,000 undergraduate students on one of Europe’s greenest campuses. Its Science Faculty is subdivided into six research institutes and neighbours the FELIX-HFML national research institute; its contributions to the ATLAS experiment (and to subatomic physics at large, as well as astroparticle and gravitational physics) are embedded in the Institute for Mathematics, Astrophysics and Particle Physics (IMAPP). Radboud University is one of the founding members of the Nikhef joint venture, and has a long history of participation in collider physics experiments.

At the University of Twente, a technical university in the east of the Netherlands, the High Energy Physics activities are embedded in the EMS research group, within the faculty for Applied Natural Science and Technology. The EMS group on "Energy, Material and Systems" has expertise on cooling technology, was instrumental in the construction and design of the ATLAS toroid magnet, and currently performs R&D for dipole magnets at future colliders (FCC-hh, Muon Collider). 

The UvA and NWO-I are equal-opportunity employers. We prioritise diversity and are committed to creating an inclusive environment for everyone. We value a spirit of enquiry and perseverance, provide the space to keep asking questions, and promote a culture of curiosity and creativity.