No-scale scenario with nonuniversal gaugino masses

Phenomenological issues of the no-scale structure of the Kähler potential are reexamined, which arises in various approaches to supersymmetry breaking. When no-scale boundary conditions are given at the grand unified scale and universal gaugino masses are postulated, a B-ino mass is quite degenerate with right-handed slepton masses and the requirement that the lightest superparticle (LSP) be neutral supplemented with slepton searches at CERN LEP200 severely constrains the allowed mass regions of superparticles. The situation drastically changes if one moderately relaxes the assumption of the universal gaugino masses. After reviewing some interesting scenarios where nonuniversal gaugino masses arise, we show that the nonuniversality diminishes the otherwise severe constraint on the superparticle masses and leads to a variety of superparticle mass spectra: in particular the LSP can be a W-ino-like neutralino, a Higgsino-like neutralino, or even a sneutrino, and also left-handed sleptons can be lighter than right-handed ones.