Direct dark matter search with the full data set of XMASS-I

  • Ko Abe Kamioka Observatory, ICRR, The Univ. of Tokyo
Keywords: dark matter, WIMP, liquid xenon, single phase, direct search


XMASS-I was unique experiment, as single phase, large volume liquid xenon detector observation was
carried out during Nov. 20, 2013 to Feb. 1, 2019. Including WIMP dark matter searches, many rare event
search results by using XMASS-I data were reported so far, such as dark photon, axion, axion-like particle,
double electron capture.
After the end of the long stable data acquisition, analysis for WIMP dark matter searches with full data
set was processed. The analysis with total accumulated live time of 1590.9 days for the normal threshold
trigger(> 1 keVee) and 768.8 days for the low threshold trigger (>0.5keVee) with 832kg of liquid xenon
have been done.
Two search analyses were done with almost 5 years long stable data set. One is the fiducial volume
analysis in which nuclear recoil signal was searched in the detector’s fiducial volume, which contained
97kg of liquid xenon. The other is the annual modulation analysis which signal was searched on all target
volumes of 832kg. In addition to nuclear recoil signal, signal from bremsstrahlung effect and Migdal effect
were also searched in the modulation analysis.
In the present circumstance for the dark matter searches, search by various methods is becoming more
important than ever. The results from XMASS-I full data set are unique and very valuable results.

Special Issue on Neutrinos and Dark Matter-2022