Antilepton
From Star Trek : Freedom's Wiki
An antilepton is an antimatter counterpart of a lepton. Antileptons interfere with subspace communications.
In 2369, Gul Jasad flooded subspace with antilepton interference near Deep Space 9 in order to halt its subspace communications with Starfleet while he was attempting to gain answers to his questions about the sudden disappearance of Gul Dukat's starship. (DS9: "Emissary")
