Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber.
Phys Rev Lett
; 114(23): 231302, 2015 Jun 12.
Article
em En
| MEDLINE
| ID: mdl-26196790
ABSTRACT
New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of <3.5×10(-10) and an alpha rejection factor of >98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.
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MEDLINE
Assunto principal:
Fluorocarbonos
/
Modelos Teóricos
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article