The DarkSide project at Laboratori Nazionali del Gran Sasso (LNGS) is a dark matter direct search experiment based on the detection of rare nuclear recoils possibly induced by hypothetical dark matter particles, which are supposed to be neutral, massive (> 10 GeV) and weakly interact- ing (WIMP).
DarkSide aims to perform background-free WIMP searches using a series of dual-phase liquid argon time projection chambers filled with ultra-pure liquid argon. The detector currently operat- ing at LNGS is DarkSide-50, a detector which holds 46 kg of active liquid argon and is now filled with argon extracted from underground and taking data in its final configuration.
Combining the underground argon data with the preceding search made with atmospheric argon, a 90% C.L. upper limit on the WIMP-nucleon spin-independent cross section of 2.0 × 10−44 cm$^2$ is set.
The next phase of the experiment foresees the construction of a new detector with an active mass of ∼ 20 and equipped with silicon photomultipliers, called DarkSide-20k.