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This content will become publicly available on July 28, 2018

Title: Direct detection of sub-GeV dark matter with scintillating targets

We suggest a novel experimental concept for detecting MeV-to-GeV-mass dark matter, in which the dark matter scatters off electrons in a scintillating target and produces a signal of one or a few photons. New large-area photodetectors are needed to measure the photon signal with negligible dark counts, which could be constructed from transition edge sensor (TES) or microwave kinetic inductance detector (MKID) technology. Alternatively, detecting two photons in coincidence may allow the use of conventional photodetectors like photomultiplier tubes. Here we describe why scintillators may have distinct advantages over other experiments searching for a low ionization signal from sub-GeV dark matter, as there are fewer potential sources of spurious backgrounds. We discuss various target choices, but focus on calculating the expected dark matter-electron scattering rates in three scintillating crystals: sodium iodide (NaI), cesium iodide (CsI), and gallium arsenide (GaAs). Among these, GaAs has the lowest band gap (1.52 eV) compared to NaI (5.9 eV) or CsI (6.4 eV), which in principle allows it to probe dark matter masses as low as ~0.5 MeV, compared to ~1.5 MeV with NaI or CsI. We compare these scattering rates with those expected in silicon (Si) and germanium (Ge). The proposed experimental concept presentsmore » an important complementary path to existing efforts, and its potential advantages may make it the most sensitive direct-detection probe of dark matter down to MeV masses.« less
 [1] ;  [2] ;  [2] ;  [3] ;  [2]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Stony Brook Univ., NY (United States). C.N. Yang Inst. for Theoretical Physics
  3. Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy
Publication Date:
Grant/Contract Number:
AC02-05CH11231; FG02-09ER16052; PHY1316617; SC0008061
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 96; Journal Issue: 1; Journal ID: ISSN 2470-0010
American Physical Society (APS)
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC); Sloan Foundation; National Science Foundation (NSF)
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1373327