Supersymmetric dark matter

When combined with the wealth of observational evidence for a nonrelativist ic matter density Omega(0) greater than or equal to 0.3, the big-bang-nucle osynthesis constraint on the baryon density, Omega less than or similar to 0.1 indicates the existence of a significant amount of nonbaryonic dark mat ter. Several lines of reasoning suggest that the dark matter consists of so me new, as yet undiscovered, weakly interacting massive particle (WIMP). Of the WIMP candidates that have been considered, perhaps the best-motivated and certainly the most theoretically developed is the neutralino, the light est supersymmetric particle (LSP) in many supersymmetric theories. There is now a vast experimental effort being mounted to detect these particles in the Galactic halo. Techniques include direct detection in low-background la boratory detectors, indirect detection through observation of energetic neu trinos from annihilation of WIMPs that have accumulated in the Sun and/or t he Earth, and observation of anomalous cosmic-ray antiprotons, positrons, a nd gamma rays. (C) 2000 Elsevier Science B.V. All rights reserved.