Neutrino backgrounds to dark matter searches

Neutrino coherent scattering cross sections can be as large as ${10}^{-39}{\mathrm{cm}}^2$, while current dark matter experiments have sensitivities to WIMP coherent scattering cross sections 5 orders of magnitude smaller; future experiments plan to have sensitivities to cross sections as small as ${10}^{-48}{\mathrm{cm}}^2$. With large target masses and few keV recoil energy detection thresholds, neutral current coherent scattering of solar neutrinos becomes an irreducible background in dark matter searches. In the current zero-background analysis paradigm, neutrino coherent scattering will limit the achievable sensitivity to dark matter scattering cross sections, at the level of ${10}^{-46}{\mathrm{cm}}^2$.

Figure 1

Left: number of solar neutrinos per ${\mathrm{cm}}^2$ per second per energy bin vs neutrino energy (MeV). Right: number of solar neutrino-nucleus coherent scattering events per ${}^{12}\mathrm{C}$ ton-year exposure, normalized per keV, vs recoil kinetic energy (keV).

Figure 2

Left: number of geo antineutrinos per ${\mathrm{cm}}^2$ per second vs neutrino energy (MeV). Right: number of geo-neutrino-nucleus coherent scattering events per ${}^{12}\mathrm{C}$ ton-year exposure, normalized per keV, vs recoil kinetic energy (keV).

Figure 3

Left: number of atmospheric neutrinos per ${\mathrm{cm}}^2$ per second vs neutrino energy (MeV). Right: number of atmospheric neutrino-nucleus coherent scattering events per ${}^{12}\mathrm{C}$ ton-year exposure, normalized per keV, vs recoil kinetic energy (keV).

Figure 4

Left: number of ${}^8\mathrm{B}$ solar neutrino-nucleus coherent scattering events per ton-year exposure in various detector media, normalized per keV, vs recoil kinetic energy (keV). Right: integrated number of neutrino-nucleus coherent scattering events above threshold per ton-year exposure in various detector media, normalized per keV, vs recoil kinetic energy threshold (keV) for ${}^8\mathrm{B}$ solar neutrinos.