lightest superpartner(LSP) The lightest particle predicted to exist by supersymmetry. The LSP must be a stable particle since there is no lighter supersymmetric particle it can decay to. The photino is a promising candidate to be the LSP. It is not possible to predict the mass of the LSP since the way in which supersymmetry is broken is not known. The LSP may contribute to the dark matter in the Universe.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006