We study the signals resulting from the production and subsequent decays of heavy sleptons, sneutrinos and all the charginos [Formula: see text] and neutralinos [Formula: see text] at ultrahigh energy e+e− colliders. In contrast to existing studies that assume that supersymmetric particles directly decay to the lightest supersymmetric particle (taken here to be the lightest neutralino, [Formula: see text]) which then escapes detection, we incorporate realistic decay patterns using the minimal supersymmetry model as a guide for the masses and mixing angles in the gaugino-Higgsino sector. We show that very heavy sleptons and sneutrinos often decay into heavier charginos and neutralinos which themselves often decay into real W and Z0 bosons and lighter [Formula: see text]'s and [Formula: see text]'s. This results in a considerably softer missing transverse momentum [Formula: see text] spectrum than would be expected if sparticles decayed directly to the [Formula: see text] so that [Formula: see text] is not necessarily a viable signature for very heavy sparticles. We show that the optimal signature for supersymmetry in very high energy e+e− collisions depends on the model parameters. Whereas [Formula: see text] is a viable signature for lighter sleptons and sneutrinos (m ~ 0.3 TeV ), the production of very heavy sparticles is signalled by events with two or more large angle W and Z0 bosons and often a very hard electron. We discuss strategies for extracting the SUSY signal and argue that it can be separated from standard model backgrounds over the whole of parameter space.
Identifying Nearby Accelerators of Ultrahigh Energy Cosmic Rays Using Ultrahigh Energy (and Very High Energy) Photons