Dark matter is one of the great enigmas of fundamental physics today. Its contribution to the total mass of the Universe is 85%, but it cannot be explained within the framework of the Standard Model of particle physics (SM). However, several candidates for dark matter exist in theories beyond the SM: this is the case of the axion, one of the best-motivated candidates as it also explains the absence of CP violation in the strong interaction.

The discovery of axions requires the invention of new experimental techniques. Several proposals have emerged in recent years. MADMAX is one of the few that is sensitive to the mass domain around 100 micro-eV, favored by theory. For this reason, it has attracted the attention of the scientific community since 2016, when it was first proposed. Today, MADMAX is a collaboration of 50 scientists from German and French laboratories (including CPPM since 2019) and is part of the DMLab International Research Laboratory, installed at DESY-Hamburg. Based on the innovative concept of dielectric haloscope, MADMAX will consist of a booster made of 80 1-meter-diameter disks that need to be positioned to micrometer precision at a temperature of 4 degrees Kelvin and in a magnetic field of 9 T. In order to realize this detector, which will take data at DESY after 2030, the MADMAX collaboration is in an R&D phase, which will be concluded by the construction and operation of a prototype whose main aim is to demonstrate the feasibility of the dielectric booster concept.

The aim of the thesis is to conduct a search for axions in an uncharted phase space by commissioning and analyzing data from the prototype. The student will contribute to the realization and mechanical characterization of the dielectric disks and their interface with the piezoelectric motors developed at CPPM. The prototype will be assembled in an experimental hall on the DESY campus, then inserted and tested at liquid helium temperature in a cryostat in 2025-2026. After these initial tests, the data from which will be analyzed by the student, the prototype will be sent to CERN for long-term tests between 2027 and 2029, under the supervision of CPPM, in a magnetic field of 1.6 T. The data analysis carried out by the student will allow to search for axions around 100 micro-eV using the innovative concept of the dielectric haloscope, with unprecedented sensitivity to axion-photon coupling.

In this context, the student will be required to make regular visits to DESY and CERN, in particular to take part in detector installation and data acquisition.

Requirements:

1. Education: master in experimental particle physics

2. Programming: knowledge in python or C++

3. Language: fluency in spoken and written English

The application consists of:

1. a motivation letter

2. CV (2 pages maximum) and university grade transcripts (for all degrees)

3. Three reference letters

More details about the CPPM Dark Matter team: https://www.cppm.in2p3.fr/web/en/research/particle_physics/#Dark%20Matter