Astronomical and cosmological observations indicate that a large amount of the energy content of the Universe is made of dark matter. The most promising dark matter candidates are the so-called WIMPs (Weakly Interacting Massive Particles).
The XENON project, at the INFN Laboratori Nazionali del Gran Sasso, consists of a double-phase Time Projection Chamber (TPC) using ultra-pure liquid xenon as both target and detection medium for dark matter particle interactions. WIMPs can be indeed detected via their elastic scattering off xenon nuclei. The XENON collaboration is now running the XENON1T experiment, the first tonne-scale liquid xenon based TPC, with an active mass inside the TPC of about 2 t. Data were collected in a live time of 279 days of dark matter search up to February 2018. The detector featured the lowest electronic recoil background ever obtained in a dark matter experiment: $(82^{+5}_{-3}(sys)\pm3 (stat))$ events/(t $\times$ yr $\times$ keV$_{ee}$). The results allowed to set the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above $6$ GeV/c$^{2}$, with a minimum of $4.1 \times 10^{-47}$ cm$^{2}$ for $30$ GeV/c$^{2}$ WIMP mass at $90\%$ confidence level.