Direct Detection of Light "Ge-phobic" Exothermic Dark Matter
  We present comparisons of direct dark matter (DM) detection data for light
WIMPs with exothermic scattering with nuclei (exoDM), both assuming the
Standard Halo Model (SHM) and in a halo model - independent manner. Exothermic
interactions favor light targets, thus reducing the importance of upper limits
derived from xenon targets, the most restrictive of which is at present the LUX
limit. In our SHM analysis the CDMS-II-Si and CoGeNT regions become allowed by
these bounds, however the recent SuperCDMS limit rejects both regions for exoDM
with isospin-conserving couplings. An isospin-violating coupling of the exoDM,
in particular one with a neutron to proton coupling ratio of $-0.8$ (which we
call "Ge-phobic"), maximally reduces the DM coupling to germanium and allows
the CDMS-II-Si region to become compatible with all bounds. This is also
clearly shown in our halo-independent analysis.
