How well will ton-scale dark matter direct detection experiments
  constrain minimal supersymmetry?
  Weakly interacting massive particles (WIMPs) are amongst the most interesting
dark matter (DM) candidates. Many DM candidates naturally arise in theories
beyond the standard model (SM) of particle physics, like weak-scale
supersymmetry (SUSY). Experiments aim to detect WIMPs by scattering,
annihilation or direct production, and thereby determine the underlying theory
to which they belong, along with its parameters. Here we examine the prospects
for further constraining the Constrained Minimal Supersymmetric Standard Model
(CMSSM) with future ton-scale direct detection experiments. We consider
ton-scale extrapolations of three current experiments: CDMS, XENON and COUPP,
with 1000 kg-years of raw exposure each. We assume energy resolutions, energy
ranges and efficiencies similar to the current versions of the experiments, and
include backgrounds at target levels. Our analysis is based on full likelihood
constructions for the experiments. We also take into account present
uncertainties on hadronic matrix elements for neutralino-quark couplings, and
on halo model parameters. We generate synthetic data based on four benchmark
points and scan over the CMSSM parameter space using nested sampling. We
construct both Bayesian posterior PDFs and frequentist profile likelihoods for
the model parameters, as well as the mass and various cross-sections of the
lightest neutralino. Future ton-scale experiments will help substantially in
constraining supersymmetry, especially when results of experiments primarily
targeting spin-dependent nuclear scattering are combined with those directed
more toward spin-independent interactions.
