Post-doctoral fellow in Particle- and Nuclear Physics Full-time NEW

Post-doctoral Fellow in Particle- and Nuclear Physics

Lund University was founded in 1666 and is repeatedly ranked among the world's top universities. The University has around 46,000 students and 8,500 staff based in Lund, Helsingborg, and Malmö. We are united in our efforts to understand, explain, and improve our world and the human condition.

This postdoc position will be part of the Lund LDMX group, LunDMX, embedded in the Division for Particle and Nuclear Physics at the Physics Department. The division, with about 60 employees, comprises a lively mixture of active research in theoretical and experimental particle and heavy ion physics as well as experimental nuclear physics. The experimental particle physics activities include research at the well-established LHC experiments ATLAS and ALICE as well as efforts to realize new, creative experiments like HIBEAM/NNBAR at ESS and – most relevant for this project – LDMX at SLAC (https://confluence.slac.stanford.edu/display/MME/Light+Dark+Matter+Experiment). We exploit synergies across these projects, and our contributions include detector development, trigger and DAQ, physics and performance analysis as well as software development and computing. The LunDMX group currently consists of a postdoc, three faculty members, and three Ph.D. students, and an engineer. This postdoc position is an important addition to our group, it will inject additional momentum to our work and strengthen our impact on the overall LDMX project. This position is also to serve as a stepping stone for the successful candidate, with ample opportunity for career development, for which we strive to give all the support we can.

The Light Dark Matter eXperiment is a fixed-target experiment planned at SLAC with the main purpose of searching for sub-GeV thermal-relic dark matter particles produced from an 8 GeV electron beam impinging on a thin target. The Lund LDMX group (LunDMX) contributes to physics analysis, detector development and performance studies as well as software development and computing. In addition, we are active in addressing sustainability questions related to developing a new particle physics experiment.

The overarching theme of this project is to get ready for LDMX data, and the work will be conducted in close connection with the international LDMX collaboration, in which Lund University is currently the only non-US participant. The main priority in this project will be to study the capabilities of LDMX to handle pile-up (multiple electrons hitting the target at the same time) in more detail. This will be based on simulation studies of potential backgrounds, detector performance, and physics sensitivities. One concrete example is the use of different codes for simulating critical backgrounds, comparing these predictions and developing methods for how to measure these backgrounds in data. The project also aims to explore to which extent machine learning methods can help with these tasks, e.g. object reconstruction and signal/background discrimination. This will be a focus in the project.

One exciting milestone for LDMX is the detector prototype system test with cosmic muons planned at SLAC in 2026. If the candidate is interested, there will be the opportunity to contribute to the analysis of this test data, mainly from the prototype of the hadronic calorimeter. Closely related to this, there is also the possibility to contribute to the characterization of the HCal electronics with a test stand locally in Lund.

There is some flexibility in the research programme for this position, and details can be tailored to your specific interests and expertise. There will also be the opportunity to work with questions of climate sustainability in LDMX/HEP.

As a postdoc in the LunDMX group, you will mainly perform simulation-based studies of different aspects feeding into the physics potential of LDMX. This will require the use (and further development) of different simulation tools, mainly the GEANT4-based ldmx-sw framework (https://github.com/LDMX-Software/ldmx-sw), written in C++, maintained on github and configured via python. You will work with .root files and explore different event generators as well as machine learning tools and algorithms. The position will also require you to contribute to the development of data-driven methods.

The nature of LDMX as an international project will require you to work collaboratively in an international research environment. Your main place of work will be at the Physics Department in Lund, but trips to SLAC/our collaborators will also be necessary. The position requires clear and thoughtful communication, both within the scientific community and with the public. You will contribute to the development and maintenance of the common LDMX software. You will be responsible for documentation and reporting of your research activities, maintaining detailed records of your work, preparing documentation for future users and following the LDMX requirements for contributing to documentation. You are expected to participate in mentorship and training of junior researchers, fostering a collaborative and knowledge-sharing environment. You will be given the opportunity to seek external research funding for travel or small projects, as well as to contribute to sustainability studies, if you wish. Your tasks will also include taking care of administration related to the duties outlined above.

Requirements for the position are:

• Doctoral degree or equivalent foreign degree in Physics. The doctoral degree must have been obtained no later than the date on which the appointment decision is made.
• Ability to develop and conduct high-quality research.
• Teaching ability
• Prior experience with simulations and data analysis in particle physics or similar
• Strong programming skills in C++ and Python
• Prior experience in the usage, development and maintenance of common software
• Collaborative skills in order to work in an international collaboration.
• Very good oral and written proficiency in English
• Scholarly proficiency, for example demonstrated through published papers and/or the quality of your PhD dissertation.
• Preparedness for international travel

Merits for the position are:

• Applicants who graduated no more than three years before the closing date for applications
• Knowledgable about interactions in the borderland energy regime between nuclear and particle physics
• Experienced in developing algorithms such as particle identification, specific final state event selection, and object reconstruction
• Prior experience with machine learning tools
• Interest and prior experience in student supervision (bachelor, master, PhD)

The assessment of applicants will primarily be based on their scientific merits and potential as researchers. Particular emphasis will be placed on scientific ability within the subject area.

Lund University is a government agency, which means that you get special benefits, generous holidays and a favourable occupational pension. Lund University has generous support for parental leave and favourable offers for training and wellness. Find out more on the University website about working with us Work for us

The position is a fixed-term position for two years, 100% with a start date of October 1, 2026, or as agreed. Employment at Lund University is based in Sweden, so you are expected to be able to perform your work on site in Lund. The position is limited to two years in accordance with the collective agreement on fixed-term employment as a postdoctoral researcher (Arbetsgivarverket). A position as a postdoctoral researcher is intended as an initial step in your career and as an opportunity to further deepen and broaden your research expertise.

If you have any questions, fell free to contact ruth.pottgen@fysik.lu.se.

Applications are submitted via the university's recruitment system, where you are also asked to answer a couple of questions. Applications shall be written in English and contain (as pdf):

• A cover letter motivating your interest in this position and how this position matches your qualifications
• A statement of your current and future research interests (up to two pages)
• A CV with copies of PhD and exam certificates. You may supply a written statement with their expected defence date.
• A list of up to 10 relevant publications, annotated with your contributions
• A list with contact information for three references Letters of recommendation are not requested at this time References will be contacted if a candidate is invited to interview
• Any other documents you wish to submit for review

Welcome to apply!