Potential-model predictions of tt-bar quark-antiquark states and the t threshold

A potential model for quark-antiquark states which fits the masses and many of the decay widths of the known mesons is used to predict masses and decay widths of systems including a sixth-flavor quark t as a function of the t-quark mass m/sub t/. Linear relations of tt-bar and D/sub t/ and D/sup asterisk//sub t/ masses as a function of m/sub t/ are given. Widths for annihilation into e+e- of the vector tt-bar states are given. Vector states should be observed with level spacings similar to psi and UPSILON. The lowest of these states should be 1.6 --1.7 GeV below t threshold