Direct Detection of Dark Matter in Supersymmetric Models

TL;DR

This work assesses neutralino-nucleon spin-independent scattering across three SUSY frameworks—mSUGRA with HB/FP behavior, SO(10) Yukawa-unified models with scalar non-universality, and 5D gaugino-mediated SUSY with non-universal gaugino masses—against relic-density and flavor/precision constraints. The analysis shows that the HB/FP region in mSUGRA yields the most promising direct-detection cross sections, particularly after relic-density rescaling, and that Stage 3 detectors could probe this region, while other regions are often beyond reach. Yukawa-unified SO(10) models are strongly constrained by relic density and unification requirements, typically yielding low direct-detection rates with only a few viable points accessible to near-future experiments. In gaugino-mediated, extra-dimensional SUSY, non-universal gaugino masses can produce sizable cross sections due to wino/higgsino components, but very low relic densities in some scenarios necessitate additional CDM components, influencing the interpretation of direct-detection prospects. Overall, the paper highlights the complementary roles of direct detection experiments and collider searches in delineating viable SUSY parameter spaces.

Abstract

We evaluate neutralino-nucleon scattering rates in several well-motivated supersymmetric models, and compare against constraints on the neutralino relic density, BF( b\to sγ) as well as the muon anomalous magnetic moment a_μ. In the mSUGRA model, the indirect constraints favor the hyperbolic branch/focus point (HB/FP) region of parameter space, and in fact this region is just where neutralino-nucleon scattering rates are high enough to be detected in direct dark matter search experiments! In Yukawa unified SUSY SO(10) models with scalar mass non-universality, the relic density of neutralinos is almost always above experimental bounds, while the corresponding direct detection rates are below experimental levels. Conversely, in five dimensional SO(10) models where gauge symmetry breaking is the result of compactification of the extra dimension, and supersymmetry breaking is communicated via gaugino mediation, the relic density is quite low, while direct detection rates can be substantial.