New experiment for WIMP direct search (NEWSdm)

Dark Matter (DM) search is one of the most significant tasks of modern physics. Direct DM searches are nowadays one of the most fervid research topics with many experimental efforts devoted to the search for nucleus recoils induced by the scattering of Weakly Interactive Massive Particles (WIMP). The new experiment NEWSdm (Nuclear Emulsions for WIMP Search - directional measurement) aimed at direct search for DM particles is based on the technologies of nuclear emulsions combining high spatial resolution and the possibility of creating large mass detectors. Emulsion detectors able to reconstruct the direction of the nuclei recoiling on he WIMP are opening a new frontier to possibly extend DM searches beyond the neutrino background. The detector concept foresees the use of a bulk of nuclear emulsion surrounded with a shield from environmental radioactivity, to be placed on an equatorial telescope in order to cancel out the effect of the Earth rotation keeping the detector at a fixed orientation toward the expected direction of galactic WIMPs. Exploiting directionality would also prove the galactic origin of DM with an unambiguous signal-to-background separation. The use in NEWSdm of fine-grained nuclear emulsions both as target and nanometric tracking device for directional DM searches gives a unique opportunity for a high-significance discovery of galactic DM. (authors)