Upsilon. (10580) r arrow J /. psi. + X in a color hybrid model

Estimates are presented for the decay width of the inclusive process {Upsilon}{sub 8}{r arrow}{ital J}/{psi}+{ital X}, where {Upsilon}{sub 8} is a color hybrid {ital b{bar b}g} of the {Upsilon}(4{ital S}) in which the {ital b} and {ital {bar b}} quarks occupy a {sup 1}{ital S}{sub 0} color-octet state. Invoking the color evaporation hypothesis, we find that {Gamma}({Upsilon}{sub 8}{r arrow}{ital J}/{psi}+{ital X}){le}{Gamma}({Upsilon}{sub 8}{r arrow}{ital c{bar c}g}){congruent}2.8 keV when the invariant mass of the {ital c{bar c}} pair is constrained to lie below the open charm threshold of 2{ital M}{sub {ital D}}. Suppression factors due to conversion of the {ital c{bar c}} pair into {ital J}/{psi} and to mixing with the color-singlet state are expected to lead to an observed rate for {Upsilon}(10580){r arrow}{ital J}/{psi}+{ital X} that is comparable to {Gamma}({Upsilon}(1{ital S}){r arrow}{ital J}/{psi}+{ital X}){congruent}60 eV, and thus consistent with experimental bounds on the non-{ital B{bar B}} decay modes of the {Upsilon}(10580).