Proposal for broad-range directional detection of light dark matter in cryogenic ice

We propose hexagonal ice (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi mathvariant="normal">H</a:mi></a:mrow><a:mrow><a:mn>2</a:mn></a:mrow></a:msub><a:mi mathvariant="normal">O</a:mi></a:mrow></a:math>) as a new target for light dark matter (DM) direct detection. Ice, a polar material, is suitable for single phonon detection through DM scattering for which we consider light dark photon and light scalar mediator models. We report a rate sensitivity down to a DM mass of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mo>∼</e:mo><e:mi>keV</e:mi></e:math>, constituting a broader mass range than other promising candidates. We find better sensitivity for near-term experimental thresholds from the presence of high-frequency phonons. These advantages, and ice’s availability, make it highly promising for single-phonon detection. Published by the American Physical Society 2024