Bounds on the Gluino Mass from a Global Parton Density Analysis

Parton distribution functions for protons are devised in which a light gluino is included along with standard model quark, antiquark, and gluon constituents. A global analysis of a large set of hadronic scattering data provides empirical constraints on the allowed range of the gluino mass as a function of the value of the strong coupling strength alpha_s(M_Z). We find that the gluino mass m_{\widetilde{g}} > 12 GeV for the standard model world-average value alpha_{s}(M_{Z})=0.118. Gluino masses as small as 10 GeV are admissible provided that alpha_s(M_Z) > 0.12, about one standard deviation above the world-average value. Current hadron scattering data are insensitive to the presence of gluinos heavier than about 100 - 150 GeV.