Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies

TL;DR

This study assesses how the Fermi LAT telescope can constrain supersymmetric dark matter models using observations of dwarf spheroidal galaxies, finding current limits are weak but future data could be more revealing.

Contribution

It provides a comprehensive analysis of the pMSSM parameter space using LAT data, highlighting the potential for future observations to probe a broader range of dark matter models.

Findings

Current LAT data cannot exclude any of the ~71,000 models at 95% confidence.

Future LAT analyses could detect some models, especially lighter LSPs (<50 GeV).

LAT and direct detection experiments are complementary in dark matter searches.

Abstract

We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of ~71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (m_LSP < 50 GeV) annihilating into tau-pairs and heavier LSPs annihilating into b-bbar. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods.