Low-mass dark matter search with CDMSlite

Abstract

The SuperCDMS experiment is designed to directly detect weakly interacting massive particles (WIMPs) that may constitute the dark matter in our Galaxy. During its operation at the Soudan Underground Laboratory, germanium detectors were run in the CDMSlite mode to gather data sets with sensitivity specifically for WIMPs with masses <10 GeV=c 2 . In this mode, a higher detector-bias voltage is applied to amplify the phonon signals produced by drifting charges. This paper presents studies of the experimental noise and its effect on the achievable energy threshold, which is demonstrated to be as low as 56 eV ee (electron equivalent energy). The detector-biasing configuration is described in detail, with analysis corrections for voltage variations to the level of a few percent. Detailed studies of the electric-field geometry, and the resulting successful development of a fiducial parameter, eliminate poorly measured events, yielding an energy resolution ranging from ∼9 eV ee at 0 keV to 101 eV ee at ∼10 keV ee . New results are derived for astrophysical uncertainties relevant to the WIMP-search limits, specifically examining how they are affected by variations in the most probable WIMP velocity and the Galactic escape velocity. These variations become more important for WIMP masses below 10 GeV=c 2 . Finally, new limits on spin-dependent low-mass WIMP-nucleon interactions are derived, with new parameter space excluded for WIMP masses ≲3 GeV=c 2 .

Strongly interacting dark sectors in the early Universe and at the LHC through a simplified portal

“…For the mass range 1 GeV m π 10 GeV that we will be interested in, relevant constraints arise from a number of different direct detection experiments, namely CRESST-III [43], CDMSLite [44], DarkSide-50 [45], PICO-60 [46], PandaX [47] and XENON1T [48]. Rather than simply considering each experimental result separately, we use DDCalc 2.0 [49] to perform a statistical combination of all experimental results.…”

Hunting for light dark matter with DUNE PRISM

“…Although dark matter (DM) is undoubtedly present in our universe, its detection via non-gravitational effects has eluded us [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. One well-motivated hypothesis regarding DM is that, in the early universe, it was in thermal equilibrium with the standard model (SM) plasma before its interactions froze out, resulting in a relic abundance that persists today [17].…”

Relation between the Migdal Effect and Dark Matter-Electron Scattering in Isolated Atoms and Semiconductors

“…Since the dipole approximation is valid when qr e 1, where r e ∼ 1/(αm e ) in silicon, we anchor our form-factors at q 0 = 0.5αm e and take the average value of f ion in a neighborhood around q 0 . The [52], CRESST III [53], organic liquid scintillator [54], DarkSide-50 [55], CDEX [6], XENON1T [56,57], and a recast of XENON1T data for cosmic-ray up-scatter [44]. In the bottom panel, the gray-shaded region corresponds to constraints from LUX [4] and Panda-X [58].…”