First results from the CRESST-III low-mass dark matter program

Abstract

The CRESST experiment is a direct dark matter search which aims to measure interactions of potential dark matter particles in an earth-bound detector. With the current stage, CRESST-III, we focus on a low energy threshold for increased sensitivity towards light dark matter particles. In this manuscript we describe the analysis of one detector operated in the first run of CRESST-III (05/2016-02/2018) achieving a nuclear recoil threshold of 30.1 eV. This result was obtained with a 23.6 g CaWO 4 crystal operated as a cryogenic scintillating calorimeter in the CRESST setup at the Laboratori Nazionali del Gran Sasso (LNGS). Both the primary phonon/heat signal and the simultaneously emitted scintillation light, which is absorbed in a separate silicon-on-sapphire light absorber, are measured with highly sensitive transition edge sensors operated at ∼ 15 mK. The unique combination of these sensors with the light element oxygen present in our target yields sensitivity to dark matter particle masses as low as 160 MeV/c 2 .

The highest-speed local dark matter particles come from the Large Magellanic Cloud

“…This is most visible in the bottom left panels of Figures 5 & 6, where we examine the ratio of g(v min ) of Solar Neighborhood . Vertical green lines represent the value of v min near the thresholds for particle scattering of a 10 GeV/c 2 DM particle in the: Xenon1T (Q min =1 keV, Xenon target) [93], LUX-ZEPLIN (Q min =3.3 keV, Xenon target) [94,95], PICO 60 (Q min =2.45 keV, Fluorine target) [96], DAMIC (Q min =0.6 keV, Silicon target) [97], SuperCDMS (Q min = 0.27 keV, Germanium target) [98], and CRESST-III (Q min =0.03 keV, Oxygen target) [99] particles (either with or without the LMC particles) after the LMC's passage relative to the isolated MW. Above a geocentric speed of 600 km/s (close to the threshold for S1 + S2 analyses of xenon nuclear recoil analysis for a 10 GeV WIMP), the LMC's passage leads to a 25% enhancement of the signal in Model 1, and nearly a factor of 2 change for Model 2.…”

ANAIS-112 status: two years results on annual modulation

“…The current statistical significance of the DAMA/LIBRA modulation result reaches the 12σ level. However, it has neither been reproduced by any other experiment, nor ruled out in a model independent way [5,6,7,8,9,10]. Compatibility among the different experimental results in most conventional WIMP-DM scenarios is actually disfavored [11,12].…”

Annual modulation in direct dark matter searches

“…CRESST-III explores even lower mass regions, having individual detector masses at 24g, an order of magnitude lower that allow even smaller heating events as well as scintillating light events from dark matter collisions to be recorded. In the first run completed in Feb 2018, CREST-III was able to achieve a nuclear recoil energy threshold of 30.1 eV nr , implying sensitivity to dark matter as low as 160MeV/c 2 [114].…”