A Possibility of Determining the WIMP Mass by Using the Angular Recoil-Energy Spectra from Directional Direct Dark Matter Detection Experiments

Abstract: In this article, as an extension of our study on the angular distribution of the recoil flux of WIMP-scattered target nuclei, we demonstrate a possibility of determining the mass of incident halo WIMPs by using or combining "ridge-crater" structures of the angular recoil-energy spectra with different target nuclei observed in directional direct Dark Matter detection experiments. Our simulation results show that, for a WIMP mass of only a few tens GeV, the stereoscopic angular recoil-flux distributions of both of light and heavy target nuclei would have a (longitudinally) "ridge-like" structure. However, once the WIMP mass is as heavy as a few hundreds GeV, the angular recoil-flux distributions of heavy target nuclei would in contrast show a (latitudinally) "crater-like" structure.