Dark Secrets of Baryons: Illuminating Dark Matter-Baryon Interactions with JWST

The James Webb Space Telescope (JWST) has discovered numerous
bright galaxies at high redshifts ($z\approx 10-14$).
Many astrophysical models and beyond the Standard Model physics scenarios
have been proposed to explain these observations. We investigate, {\it for
the first time}, the implications of dark matter (DM) scattering with
baryons (protons and electrons) in light of the JWST UV luminosity function
(UVLF) observations. These interactions suppress structure formation on
galactic scales, which may have an observable effect on the UVLF
measurements at high redshifts. Using a recent galaxy formation model
designed to explain high redshift observations, we obtain strong upper
limits on DM-baryon scattering cross-sections and explore new regions of
the parameter space. For DM-proton scattering with cross-section $\propto
v^{-2}$ velocity dependence, we obtain the strongest limit for DM masses of
$\sim$ 1 -- 500 MeV. For other cases that we study (DM-proton scattering
cross-section $\propto v^{0},\,v^{-4}$ and DM-electron scattering
cross-section $\propto v^{0},\,v^{-2},\,v^{-4}$, our limits are competitive
with those obtained from other cosmological observables.
Our study highlights the potential of JWST observations as a novel and
powerful probe of non-gravitational interactions of DM.