  Models beyond the Standard Model have been proposed to simultaneously solve
the problems of naturalness and neutrino mass, in which heavy Majorana
neutrinos and vector-like top partners are usually predicted. A new decay
channel of the top partner mediated by the heavy Majorana neutrino can thus
appear: $T\to b\,W^{+}\to b\,\ell^{+}\ell^{+}q\bar{q'}$. We study in this paper
the observability of this decay process through single production of the top
partner at the 14 TeV LHC: $pp\to T/\bar{T}$+jets$\to
b/\bar{b}+\mu^{\pm}\mu^{\pm}$+jets. $2\sigma$ exclusion bounds on the top
partner mass and mixing parameters are given by Monte-Carlo simulation, which
surpass those from the search through VLT pair production in the mass range of
$m_{T}>1.3$ TeV.
