The lightest neutralino is a natural candidate for the dark matter in the Universe. It is very nearly a pure bino or a symmetric or antisymmetric higgsino over a wide region of parameter space of the supersymmetric standard model. We consider here their elastic scattering off of matter in the laboratory. We find that while binos are very much like photinos, the symmetric or antisymmetric higgsinos would be invisible to proposed laboratory detectors.
Bibliographical noteFunding Information:
The work of K.A.O. was supportedi n part by DOE-AC02-83ER-40105 and by a Presidential Young Investigator Award. The work of M.S. was supported in part by NSF grant PHY-86-141 85and by a Alfred P. Sloan ResearchF ellowship.