Can dark matter be stabilized by charge conservation , just as the electron is in the standard model ?
We examine the possibility that dark matter is hidden , that is , neutral under all standard model gauge interactions , but charged under an exact U ( 1 ) gauge symmetry of the hidden sector .
Such candidates are predicted in WIMPless models , supersymmetric models in which hidden dark matter has the desired thermal relic density for a wide range of masses .
Hidden charged dark matter has many novel properties not shared by neutral dark matter : ( 1 ) bound state formation and Sommerfeld-enhanced annihilation after chemical freeze out may reduce its relic density , ( 2 ) similar effects greatly enhance dark matter annihilation in protohalos at redshifts of z \sim 30 , ( 3 ) Compton scattering off hidden photons delays kinetic decoupling , suppressing small scale structure , and ( 4 ) Rutherford scattering makes such dark matter self-interacting and collisional , potentially impacting properties of the Bullet Cluster and the observed morphology of galactic halos .
We analyze all of these effects in a WIMPless model in which the hidden sector is a simplified version of the minimal supersymmetric standard model and the dark matter is a hidden sector stau .
We find that charged hidden dark matter is viable and consistent with the correct relic density for reasonable model parameters and dark matter masses in the range 1 ~ { } \text { GeV } \lesssim m _ { X } \lesssim 10 ~ { } \text { TeV } .
At the same time , in the preferred range of parameters , this model predicts cores in the dark matter halos of small galaxies and other halo properties that may be within the reach of future observations .
These models therefore provide a viable and well-motivated framework for collisional dark matter with Sommerfeld enhancement , with novel implications for astrophysics and dark matter searches .