Heavy superheated droplet detectors as a probe of spin-independent WIMP dark matter existence

Abstract

At present, application of Superheated Droplet Detectors (SDDs) in WIMP dark matter searches has been limited to the spin-dependent sector, owing to the general use of fluorinated refrigerants which have high spin sensitivity. Given their recent demonstration of a significant constraint capability with relatively small exposures and the relative economy of the technique, we consider the potential impact of heavy versions of such devices on the spin-independent sector. Limits obtainable from a ${\mathrm{CF}}_{3}\mathrm{I}$-loaded SDD are estimated on the basis of the radiopurity levels and backgrounds already achieved by the SIMPLE and PICASSO experiments. With 34 kgd exposure, equivalent to the current CDMS, such a device may already probe to below ${10}^{\ensuremath{-}6}\text{ }\text{ }\mathrm{pb}$ in the spin-independent cross section.