Scrutinizing supergravity models through neutrino telescopes.

Galactic halo neutralinos ([chi]) captured by the Sun or Earth produce high-energy neutrinos as end products of various annihilation modes. These neutrinos can travel from the Sun or Earth cores to the neighborhood of underground detectors ( neutrino telescopes'') where they can interact and produce upwardly moving muons. We compute these muon fluxes in the context of the minimal SU(5) supergravity model, and the no-scale and dilaton SU(5)[times]U(1) supergravity models. At present, with the Kamiokande 90% C.L. upper limits on the flux, only a small fraction of the parameter space of the SU(5)[times]U(1) models is accessible for [ital m][sub [chi]][similar to][ital m][sub Fe], which in turn implies constraints for the lightest chargino mass around 100 GeV for a range of tan [beta] values. We also delineate the regions of parameter space that would be accessible with the improvements of experimental sensitivity expected in the near future at Gran Sasso, Super-Kamiokande, and other facilities such as DUMAND and AMANDA, currently under construction. We conclude that if neutralinos are present in the halo, then this technique can be used to eventually explore more than half of the allowed parameter space of these specific models, and more generally of a large class ofmore » supergravity models, in many ways surpassing the reach of traditional collider experiments.« less