We study properties of the lightest neutralino (χ 0) and calculate its cosmological relic density in a supersymmetric U(1)′ model with a secluded U(1)′ breaking sector (the S-model). The lightest neutralino mass is smaller than in the minimal supersymmetric standard model; for instance, m χ0≲100 GeV in the limit that the U(1)′ gaugino mass is large compared to the electroweak scale. We find that the Zχ 0χ 0 coupling can be enhanced due to the singlino components in the extended neutralino sector. Neutralino annihilation through the Z-resonance then reproduces the measured cold dark matter density over broad regions of the model parameter space.
|Original language||English (US)|
|Number of pages||12|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - Oct 21 2004|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics