Searching for the Dark Matter Wind in DarkSide-20k

A variety of astrophysical observations indicate that 85% of the matter in the universe is 'dark', and the nature of these dark matter particles is unknown. Motion of the Earth through the dark matter halo of our galaxy produces an apparent wind of dark matter particles blowing opposite to the Earth's motion, with sidereal modulation in the dark matter wind direction as the Earth rotates. Detectors capable of direction-sensitive detection can search for this modulation, which would enable unambiguous identification of dark matter candidate interactions as coming from the galactic dark matter halo. The DarkSide-20k detector employs a 50 tonne time projection chamber filled with liquid argon extracted from underground, instrumented with silicon photomultiplier (SiPM) readout, to search for dark matter interactions. This project will search for evidence of dark matter interactions in the silicon of the SiPM array, whose structure gives sensitivity to search for the sidereal modulation effect for interactions in the silicon.