  Weakly interacting massive particles (WIMPs) are one of the leading
candidates for Dark Matter. So far we can use direct Dark Matter detection to
estimate the mass of halo WIMPs only by fitting predicted recoil spectra to
future experimental data. Here we develop a model-independent method for
determining the WIMP mass by using experimental data directly. This method is
independent of the as yet unknown WIMP density near the Earth as well as of the
WIMP-nuclear cross section and can be used to extract information about WIMP
mass with O(50) events.
