Probing below the neutrino floor with the first generation of stars

A new window into the cosmic dawn will soon be opened by the James Webb Space Telescope. We show that the mere observation of the first stars (Pop~III stars) in the universe can be used to place tight constraints on the strength of the interaction between dark matter and regular, baryonic matter. We apply this technique to a candidate Pop~III stellar complex discovered with the Hubble Space Telescope at redshift ~7 and find some of the deepest bounds to-date for both spin-dependent and spin-independent DM-nucleon interactions, over a large swath of DM particle masses. Additionally, we show that the most massive Pop~III stars could be used to bypass the main limitations of direct detection experiments: the neutrino background to which they will be soon sensitive.