Direction-sensitive dark matter search with a low-background gaseous detector NEWAGE-0.3b''

TL;DR

This paper reports a direction-sensitive dark matter search using a low-background gaseous detector, setting the most stringent upper limit on WIMP-proton cross section to date from such experiments.

Contribution

It introduces a low-background micro pixel chamber and conducts a novel directional analysis, improving constraints on dark matter interactions.

Findings

No significant forward-backward asymmetry observed.

Set a 90% CL upper limit of 50 pb on WIMP-proton cross section at 100 GeV/c2.

Achieved the most stringent limit from direction-sensitive dark matter searches.

Abstract

NEWAGE is a direction-sensitive dark matter search using a low-pressure gaseous time projection chamber. A low alpha-ray emission rate micro pixel chamber had been developed in order to reduce background for dark matter search. We conducted the dark matter search at the Kamioka Observatory in 2018. The total live time was 107.6 days corresponding to an exposure of 1.1 kg${\cdot}$days. Two events remained in the energy region of 50-60 keV which was consistent with 2.5 events of the expected background. A directional analysis was carried out and no significant forward-backward asymmetry derived from the WIMP-nucleus elastic scatterings was found. Thus a 90% confidence level upper limit on Spin-Dependent WIMP-proton cross section of 50 pb for a WIMP mass of 100 GeV/c2 was derived. This limit is the most stringent yet obtained from direction-sensitive dark matter search experiments.