Results of the 1 tonne × year WIMP search with XENON1T

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 Gran Sasso National Laboratory (LNGS), consists of a double-phase time projection chamber (TPCs) using ultrapure liquid Xenon as both target and detection medium for dark matter particle interactions. The WIMPs can be indeed detected via their elastic scattering off Xenon nuclei. The XENON Collaboration is now running the XENON1T experiment, the first ton 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 presents the lowest electronic recoil background ever obtained in a dark matter experiment: (82+5 −3(sys) ± 3(stat)) events/(t × yr × keVee). 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/c2, with a minimum of 4.1 × 10−47 cm2 for 30 GeV/c2 WIMP mass at 90% confidence level