APS/Alan Stonebraker

APS/Alan Stonebraker

Direct Detection

Dark matter particles are constantly streaming through the Earth, though they interact so weakly that we never notice.  Ultra-sensitive experiments are trying to detect these particles by looking for nuclei or electrons that recoil after colliding with dark matter particles in a target.  Current experiments are probing the parameter space relevant for Weakly Interacting Massive Particles, however new approaches are needed to broaden sensitivity to dark matter of lighter mass.  Our group is developing new experimental strategies to search for dark matter down to the keV-MeV range.  For example, we recently proposed a directional dark matter search that uses graphene targets, which can be implemented by the PTOLEMY experiment at Princeton.  

In addition, we study unique features of dark matter signals in such direct detection experiments.  For example, we recently showed (as illustrated in the image) that the dark matter is focused by the gravitational potential of the Sun, affecting the phase of an annual modulation signal.

[PRL Physics Synopsis]