Closing the window on high-mass strongly interacting dark matter

Abstract

New and improved constraints are placed on the spin-independent interaction cross section of dark matter with regular matter by refining two methods. First, dark matter–cosmic ray interactions are considered, wherein cosmic ray protons collide with dark matter to contribute to the gamma ray sky. This constraint is developed using the NFW, Moore, and Einasto dark matter density profiles and new data from the Fermi gamma ray space telescope. Second, the Earth capture scenario is considered, wherein particles that are captured self-annihilate at Earth's center, thus adding to its internal heat flow. The constraint presented here is based on analysis of the drift time of dark matter particles through Earth, modeled as a core composed of iron and a mantle composed of oxygen with linear density gradients between layers. An analysis of the cosmic ray constraint (which rules out dark matter–regular matter interaction cross sections greater than its value) shows that it overlaps considerably with the Earth drift time constraint (which rules out cross sections smaller than its value). Most significantly, the new cosmic ray constraint excludes the last remaining open region for strongly interacting dark matter particles up to a mass of about 1017 GeV when combined with other exclusions, closing the window for strongly interacting dark matter.