DarkSide50 results from first argon run

TL;DR

DarkSide-50, a liquid argon TPC dark matter detector at Gran Sasso, collected extensive atmospheric argon data without observing expected 39Ar background, demonstrating detector capabilities and future scalability.

Contribution

First detailed results from DarkSide-50 using atmospheric argon, showing no 39Ar background and outlining plans for a larger detector with improved sensitivity.

Findings

No 39Ar background observed at current sensitivity

Detector successfully collected over 10^7 events

Plans for multi-ton detector with enhanced sensitivity

Abstract

DarkSide (DS) at Gran Sasso underground laboratory is a direct dark matter search program based on TPCs with liquid argon from underground sources. The DS-50 TPC, with 50 kg of liquid argon is installed inside active neutron and muon detectors. DS-50 has been taking data since Nov 2013, collecting more than 10^7 events with atmospheric argon. This data represents an exposure to the largest background, beta decays of 39Ar, comparable to the full 3 y run of DS-50 with underground argon. When analysed with a threshold that would give a sensitivity in the full run of about 10^-45 cm2 at a WIMP mass of 100 GeV, there is no 39Ar background observed. We present the detector design and performance, the results from the atmospheric argon run and plans for an upscale to a multi-ton detector along with its sensitivity.