Closing the light gluino window

The running of the strong coupling constant, $R_{e^{+}{e}^{-}},R_Z$ and $R_{\tau }$ is studied on the three-loop level. Based on experimental data of $R_{e^{+}{e}^{-}},R_Z$ and $R_{\tau }$ and the LEP multijet analysis, the light gluino scenario is excluded to 99.97% CL (window I) and 99.89% CL (window III).