We analyze the dark matter problem in the context of the supersymmetric $U(1{)}_{B-L}$ model. In this model, the lightest neutralino can be the $B-L$ gaugino ${\tilde{Z}}_{B-L}$ or the extra Higgsinos ${\tilde{\chi }}_{1,2}$ dominated. We compute the thermal relic abundance of these particles and show that, unlike the lightest neutralino in the MSSM, they can account for the observed relic abundance with no conflict with other phenomenological constraints. The prospects for their direct detection, if they are part of our galactic halo, are also discussed.

• Received 22 November 2008

DOI:https://doi.org/10.1103/PhysRevD.79.083510