A string no-scale supergravity model and its experimental consequences

We propose a string-derived model based on the gauge group SU(5)\times U(1) which satisfies the stringent constraints from no-scale supergravity, allows gauge coupling unification at the string scale, and entails previously unexplored correlations among various sectors of the model. All supersymmetric observables are given in terms of a single mass parameter with self-consistency of the model determining the rest, including \tan\beta=2.2-2.3 and m_t\approx175\GeV. A small non-universality of the scalar masses at the string scale produces a downward shift in the right-handed slepton masses at the electroweak scale, such that for m_{1/2}\gsim180\GeV these particles become lighter than the lightest neutralino. This cutoff in the parameter space entails the imminent discovery of charginos at the Tevatron via trilepton events (m_{\chi^\pm_1}<90\GeV). Also, the lightest Higgs boson (m_h<90\GeV), the lightest chargino, and the right-handed sleptons (m_{\tilde\ell_R}<50\GeV) should be readily observable at LEPII. We also discuss the model predictions for B(b\to s\gamma) (g-2)_\mu, R_b, and the prospects for direct neutralino dark matter detection.