Global fits of the dark matter-nucleon effective interactions
  The effective theory of isoscalar dark matter-nucleon interactions mediated
by heavy spin-one or spin-zero particles depends on 10 coupling constants
besides the dark matter particle mass. Here we compare this 11-dimensional
effective theory to current observations in a comprehensive statistical
analysis of several direct detection experiments, including the recent LUX,
SuperCDMS and CDMSlite results. From a multidimensional scan with about 3
million likelihood evaluations, we extract the marginalized posterior
probability density functions (a Bayesian approach) and the profile likelihoods
(a frequentist approach), as well as the associated credible regions and
confidence levels, for each coupling constant vs dark matter mass and for each
pair of coupling constants. We compare the Bayesian and frequentist approach in
the light of the currently limited amount of data. We find that current direct
detection data contain sufficient information to simultaneously constrain not
only the familiar spin-independent and spin-dependent interactions, but also
the remaining velocity and momentum dependent couplings predicted by the dark
matter-nucleon effective theory. For current experiments associated with a null
result, we find strong correlations between some pairs of coupling constants.
For experiments that claim a signal (i.e., CoGeNT and DAMA), we find that pairs
of coupling constants produce degenerate results.
