Neutralino dark matter in mirage mediation

Abstract

We study the phenomenology of neutralino dark matter (DM) in a mirage mediation scenario of supersymmetry breaking which results from the moduli stabilization in some string/brane models. Depending upon the model parameters, especially the anomaly to modulus mediation ratio determined by the moduli stabilization mechanism, the nature of the lightest supersymmetric particle (LSP) changes from bino-like neutralino to Higgsino-like neutralino via a bino-Higgsino mixing region. For the bino-like LSP, the standard thermal production mechanism can give the right amount of relic DM density through the stop/stau-neutralino coannihilation or the pseudoscalar Higgs resonance process. We also examine the prospect of direct and indirect DM detection in various parameter regions of mirage mediation. Neutralino DM in the galactic halo might be detected by near future direct detection experiments in the case of the bino-Higgsino mixed LSP. The gamma ray flux from the galactic centre might be detectable also if the DM density profile takes a cuspy shape. ©2006 IOP Publishing Ltd and SISSA.