DESY Theory Seminar

Searching for Ultralight Dark Matter Using Precision Spectroscopy

by Abhishek Banerjee (Weizmann Insitutue of Science)




In this talk (based on:, I will describe how to use precision spectroscopy (atomic clocks) to search for ultralight dark matter (DM). In particular, the coupling of ultralight dark matter (ULDM) to the QCD parameters would lead to an oscillation of the nuclear charge radius for both the quantum chromodynamics (QCD) axion and scalar DM. Consequently, the resulting oscillation of electronic energy levels could be resolved with optical atomic clocks, and their comparisons can be used to investigate UDM-nuclear couplings, which were previously only accessible with other platforms. Using a state-of-the-art optical atomic clock, we find bounds on the scalar ULDM-nuclear couplings and the QCD axion decay constant. These results are at a similar level compared to the most stringent spectroscopic limits, and future investigations, also with other optical clocks, promise significant improvements.