A New Model-Independent Method for Extracting Spin-Dependent Cross   Section Limits from Dark Matter Searches
  A new method is proposed for extracting limits on spin-dependent WIMP-nucleon interaction cross sections from direct detection dark matter experiments. The new method has the advantage that the limits on individual WIMP-proton and WIMP-neutron cross sections for a given WIMP mass can be combined in a simple way to give a model-independent limit on the properties of WIMPs scattering from both protons and neutrons in the target nucleus. Extension of the technique to the case of a target material consisting of several different species of nuclei is discussed. 
D. R. Tovey, R. J. Gaitskell, P. Gondolo, Y. Ramachers, L. Roszkowski