Search for Axion-Like Dark Matter and Exotic Yukawa-Like Interaction

General ILL Seminar organised by College 3
ILL50 101 seminar room
Friday, 4 November 2022 at 11h00

Zoom info for remote connection: https://ill.zoom.us/j/93176246650?pwd=bjc2d3lLMk53cUFUN1ZGWVNTTGdLQT09
Passcode: 399521

Ivo Schultess
Laboratory for High Energy Physics (LHEP), University of Bern
Institut Laue-Langevin, Grenoble, France
ivo.schulthess@lhep.unibe.ch

Besides the undoubted success of the Standard Model of particle physics, it fails to answer many longstanding questions. These include the observed dark matter and the baryon asymmetry in our universe. Many theoretical models that try to answer those questions require new particles and gauge bosons which have to be verified or excluded experimentally.
In this talk, I will present the search for two such candidates. The first candidate are ultralight pseudo-scalar particles called axion-like particles (ALPs).  We searched for them using a Ramsey-type apparatus at the ILL's cold neutron beam facility PF1b. A hypothetical coupling of ALPs to gluons would manifest in a neutron electric dipole moment signal oscillating in time. Twenty-four hours of data have been analyzed in a frequency range from 23 μHz to 1 kHz, and no significant oscillating signal has been found. The usage of present dark-matter models allows for constraining the coupling of ALPs to gluons. The second candidate is an axial-vector gauge boson that could mediate a Yukawa-like interaction in the millimeter range between Standard Model fermions. We built a tabletop experiment similar to the setup used to measure the neutron magnetic moment at the ILL in 1979. The setup applies Ramsey's technique to the proton spins of hydrogen in water. We performed a proof-of-principle search for this exotic interaction and measured radio-frequency effects like the Bloch-Siegert shift and dressed spin states.

Caterina Michelagnoli (College 3 Secretary)