Closing the Light Gluino Window in Supersymmetric Grand Unified Models

Abstract

We study the light gluino scenario giving special attention to constraints from the masses of the light CP-even neutral Higgs $m_h$, the lightest chargino $m_{{\chi }_1^{\pm }}$, and the second lightest neutralino $m_{{\chi }_2^0}$, and from the $b\to s\gamma$ decay. We find that minimal $N=1$ supergravity, with a radiatively broken electroweak symmetry group and universality of scalar and gaugino masses at the unification scale, is incompatible with the existence of a light gluino.

Comments: 12 pages (plain tex), 1 figure not included, VAND-TH-94-7-R. An error is corrected. Modifications to the text and the figure are made