= Solution
Top decay occurs before a <Hadronization>[colour-bound] hadron can form. Using representative scales $\Gamma_t\sim1$–$1.5\,\mathrm{GeV}$ and $\Lambda_{\mathrm{QCD}}\sim0.2\,\mathrm{GeV}$,
$$
\boxed{\tau_t\sim\frac\hbar{\Gamma_t}\sim5\times10^{-25}\,\mathrm s
<\tau_{\mathrm{had}}\sim\frac\hbar{\Lambda_{\mathrm{QCD}}}\sim3\times10^{-24}\,\mathrm s.}
$$
Thus <top quarks> do not live long enough to form ordinary top-containing mesons. The decay products still participate in <QCD> radiation and <hadronization>, so “free decay” here means decay before binding, not a stable observable free <Color charge>[coloured] asymptotic particle.
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