Speaker
Description
Determining the dark-matter mass is important for interpreting signals in direct-detection experiments. However, this can be challenging for low-threshold detectors with limited recoil-energy information. We present a method to estimate the dark-matter mass using directional information in (effectively) two-dimensional detectors. The motion of the Solar System and the Earth through the Galactic halo induces a dark-matter wind, which makes the event rate depend on the angle between the detector plane and the dark-matter wind. We show that the shape of this angular dependence, especially how sharply it changes with angle, contains information on the dark-matter mass. As a concrete example, we apply the method to a graphene Josephson-junction detector and confirm the expected angular dependence with numerical rate calculations. We also develop a code, DarkWind, to calculate the angle between the detector plane and the dark-matter wind as a function of time and detector location in a realistic experimental setup.