Detecting Composite Dark Matter with Long Range and Contact Interactions
  in Gas Clouds
  Cold interstellar gas clouds provide an exciting new method to discover dark
matter. Their immense size makes them uniquely sensitive to interactions from
the heaviest, most rarefied dark matter models. Using gas cloud observations,
we derive constraints on heavy composite dark matter coupled to the Standard
Model through a light dark photon for dark matter up to a thousand solar
masses. We find gas clouds are also sensitive to very large composite dark
matter that interacts with nuclei through a fixed contact interaction cross
section. We also study the contact interaction model and implement multiscatter
and overburden analyses to obtain bounds from experiments like CDMS, CRESST,
DAMA, XQC, and XENON1T.
