Few arguments on comparisons with some model dependent results
... and more ...
For example, large differences are expected in the counting rate for instance among nuclei
fully sensitive to the SD interaction (as 23Na and 127I)
with the respect to nuclei largely insensitive to such a coupling
(as e.g natGe, natSi, natAr, natCa,
natW, natO) and also when nuclei in principle all sensitive
to this coupling but having different unpaired nucleon (e.g. neutron in case of
the odd spin nuclei, such as 129Xe, 131Xe, 125Te,
73Ge, 29Si, 183W
and proton in the 23Na and 127I). In addition, the
very large existing uncertainties on e.g. form factors, spin
factors, etc. for each nuclides always largely decouple results.
In case the detection of the DM particles would involve electromagnetic signals (see, for example,
the case of the light bosons discussed above), all the experiments, such as e.g. CDMS, EDELWEISS, CREST, ZEPLIN, WARP, XENON
do lose the DM signal in the rejection procedures of the e.m. contribution to the counting rate.
It is also worth to note that no results obtained with different target nuclei can intrinsecally
be directly compared even for the same kind of coupling. In fact, this requires -- among others --
the knowledge of the scaling laws among the DM particle-nuclear cross sections,
situation even worse than that in the field of double beta decay experiments when different materials are used.
As regards the indirect searches, a comparison
would always require the calculation and the consideration of
all the possible DM particle configurations in the
given particle model, since it does not exist
a biunivocal correspondence between the observables in the
two kinds of experiments: DM particle-nucleus elastic
scattering cross section (direct detection case) and flux of
either muons from secondary neutrinos or antimatter or photons following
DM annihilations (indirect detection cases).