Extensive air showers from ultrahigh energy gluinos

We study the proposal that the cosmic ray primaries above the Greisen-Zatsepin-Kuzmin cutoff are gluino-containing hadrons ((g) over tilde hadrons). We describe the interaction of (g) over tilde hadrons with nucleons in the framework of the Gribov-Regge approach using a modified version of the hadronic interaction model QGSJET for the generations of extensive air showers (EAS's). There are two mass windows marginally allowed for gluinos: m(g)less than or similar to3 GeV and 25less than or similar tom(g)less than or similar to35 GeV. Gluino-containing hadrons corresponding to the second window produce EAS's very different from the observed ones. Light (g) over tilde hadrons corresponding to the first gluino window produce EAS's similar to those initiated by protons, and only future detectors will be able to marginally distinguish them. We propose a beam-dump accelerator experiment to search for (g) over tilde hadrons in this mass window. We emphasize the importance of this experiment: it can discover (or exclude) the light gluino and its role as a cosmic ray primary at ultrahigh energies.