Low-Mass Results from XENON1T

Using the charge signal (S2) only, XENON1T places tight constraints on various low-mass dark matter models.

Spin-independent scattering.

In a new publication, the XENON1T collaboration reports several constraints on light dark matter (DM) models based on an analysis which is using ionization signals only ("S2-only analysis"). Backgrounds are mitigated by means of strong event selections, leaving an effective exposure of (22 +- 3) tonne-days. The background above a lower threshold of ~0.4 keVee (electron equivalent) is more than 1000x lower than in similar searches with other detectors. This kind of search can only place limits on dark matter interactions since no complete background model exists. The new results from XENON1T covers previously unexplored parameter spaces for spin-independent and spin-dependent WIMP-nucleus scattering in the dark matter mass range from 3-6 GeV/c², for dark matter-electron scattering for masses > 30 MeV/c², and for absorption of dark photons and axion-like particles with a mass between 0.186 and 1 keV/c².

Light Dark Matter Search with Ionization Signals in XENON1T
E. Aprile et al. (XENON Collaboration)
Phys. Rev. Lett. 123, 251801 (2019), arXiv:1907.11485.
Explanatory "Synopsis" article on the results published in Physics