Abstract
Data from the operation of a bubble chamber filled with 3.5 kg of CF 3I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during an effective exposure of 28.1kgday, consistent with a neutron background. This observation provides strong direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering for WIMP masses >20GeV/c2.
Original language | English (US) |
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Article number | 021303 |
Journal | Physical review letters |
Volume | 106 |
Issue number | 2 |
DOIs | |
State | Published - 2011 |
ASJC Scopus subject areas
- Physics and Astronomy(all)