  In the WIMP scenario, there is a one-to-one relation between the dark matter
(DM) relic density and spin independent direct detection rate if both the
annihilation of DM and its elastic scattering on nuclei go dominantly through
Higgs exchange. In particular, for DM masses much smaller than the Higgs boson
mass, the ratio of the relevant cross sections depends only on the DM mass.
Assuming DM mass and direct detection rate within the ranges allowed by the
recent DAMA collaboration results -taking account of the channelling effect on
energy threshold and the null results of the other direct detection
experiments- gives a definite range for the relic density. For scalar DM
models, like the Higgs portal models or the inert doublet model, the relic
density range turns out to be in agreement with WMAP. This scenario implies
that the Higgs boson has a large branching ratio to pairs of DM particles, a
prediction which might challenge its search at the LHC.
