Recoil Detection of the Lightest Neutralino in MSSM Singlet Extensions

Abstract

We investigate the correlated predictions of singlet extended MSSM models for direct detection of the lightest neutralino with its cosmological relic density. To illustrate the general effects of the singlet, we take heavy sleptons and squarks. We apply LEP, $(g-2)_\mu$ and perturbativity constraints. We find that the WMAP upper bound on the cold dark matter density limits much of the parameter space to regions where the lightest neutralino can be discovered in recoil experiments. The results for the NMSSM and UMSSM are typically similar to the MSSM since their light neutralinos have similar compositions and masses. In the n/sMSSM the neutralino is often very light and its recoil detection is within the reach of the CDMS II experiment. In general, most points in the parameter spaces of the singlet models we consider are accessible to the WARP experiment.