# First Dark Matter Search Results from the XENON1T Experiment

## TL;DR

The XENON1T experiment conducted the first dark matter search with a 2000-kg xenon detector, achieving unprecedented background levels and setting the most stringent limits on WIMP interactions for masses above 10 GeV/c².

## Contribution

This work presents the first results from XENON1T, demonstrating its low background and setting new leading limits on WIMP-nucleon cross sections at a ton-scale.

## Key findings

- Achieved the lowest electronic recoil background in a dark matter detector.
- Set the most stringent exclusion limits on WIMP-nucleon cross sections for masses above 10 GeV/c².
- Data is consistent with background-only hypothesis.

## Abstract

We report the first dark matter search results from XENON1T, a $\sim$2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042$\pm$12) kg fiducial mass and in the [5, 40] $\mathrm{keV}_{\mathrm{nr}}$ energy range of interest for WIMP dark matter searches, the electronic recoil background was $(1.93 \pm 0.25) \times 10^{-4}$ events/(kg $\times$ day $\times \mathrm{keV}_{\mathrm{ee}}$), the lowest ever achieved in a dark matter detector. A profile likelihood analysis shows that the data is consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10 GeV/c${}^2$, with a minimum of 7.7 $\times 10^{-47}$ cm${}^2$ for 35-GeV/c${}^2$ WIMPs at 90% confidence level.