We study gauge mediation models of supersymmetry breaking with a neutralino lightest supersymmetric particle (LSP). These models are naturally realized by embedding the usual four-dimensional gauge mediation models into a higher-dimensional spacetime such as $M^4\times S^1{/Z}_2.$ We calculate the relic abundance of the neutralino LSP in these models and show that there exist wide parameter regions where the neutralino LSP constitutes the dominant component of the cold dark matter. These regions evade constraints from collider experiments, such as Higgs boson mass bounds, and give values for $\overrightarrow{b}s\gamma$ and the muon anomalous magnetic moment consistent with current experiments.

• Received 7 July 2003

DOI:https://doi.org/10.1103/PhysRevD.68.075005