  In the Born approximation, as in the next-to-leading order approximation,
Single lepton production $p\bar{p}\rightarrow l^{\pm}\nu X$ at Fermilab
Tevatron is discussed. The effects of non standard model physics ($W'$ -
production) are also considered. It was shown that $2\rightarrow 3$
subprocesses play important role when a high transverse momentum cut on the
lepton is imposed. On the other hand the NLO corrections do not cause
qualitative changes of Born approximation results. The contributions of $W'$
bosons for this signature become more important for large values of
$P_{T}^{cut}$.
