  Heavy $t' \to bW$ is currently being searched for at the Tevatron, but a
broader spectrum should be explored at the LHC. For $m_{b'} < m_{t'}$, we
discuss the two decay branches, $b' \to tW^*$ and $t^*W$, below the $tW$
threshold, and how they merge with $b' \to tW$ above threshold. We use a
convolution method with five body final state, and compare the production cross
section with PYTHIA. This can be extended for a $b'$ with mass heavier than
$t'$. A similar discussion is given for $t'$ decay, considering $t' \to
b^{(*)}W^{(*)}$ processes, besides the $t' \to bW$ considered by CDF.
