Speaker
Description
The Migdal effect predicts that the scatter of a neutral particle with a nucleus can result in atomic excitation or ionization. In liquid xenon dark matter detectors, the additional Migdal energy deposition enhances observable scintillation and ionization signals, and elevates a fraction of dark matter interactions from below the detector thresholds to above thresholds. Therefore, the Migdal effect can substantially enhance the sensitivity of existing experiments to interactions of sub-GeV mass dark matter candidates. We carried out a direct search for the Migdal effect in liquid xenon using O(10^5) xenon recoils in the keV region produced by scatters of 14.1MeV neutrons in a compact xenon time projection chamber. This data is predicted to contain thousands of Migdal interactions, of which a few hundred should produce observable signatures. We search for these signals in a way that is minimally impacted by uncertainties in nuclear cross section data or inaccuracies from modeling the detector response to nuclear recoils. The result of this search and the implications for dark matter experiments will be discussed.
Prepared by LLNL under Contract DE-AC52-07NA27344 (LLNL-ABS-848169).
| Submitted on behalf of a Collaboration? | No |
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