1.
Phys Rev Lett
; 106(2): 021303, 2011 Jan 14.
Artículo
en Inglés
| MEDLINE
| ID: mdl-21405218
RESUMEN
Data from the operation of a bubble chamber filled with 3.5 kg of CF3I 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 28.1 kg day, 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 >20 GeV/c2.