  On-shell effective theory approach has been widely used in search of various
supersymmetric signals, in particular, gluino/squark pairs with long cascade
decay chains in which complete matrix element calculations may encounter
over-20 dimensional integrations. On the other hand, leptons from polarized
chargino decays may show significant boost or anti-boost effect in some
scenarios and simulation without polarization information may underestimate or
overestimate the lepton $p_{T}$ cut efficiencies in the first place. We study
the polarization effects in supersymmetry searches of multi-jets plus leptons
final states. We find it justifiable for first two generations to only use
on-shell effective theories. While for measurements related to third generation
squarks, for instance, polarization effect of charginos from stop may reduce
the lepton $p_{T}$ cut efficiencies in cross section measurements by $25\%$
when slepton contributions dominate in chargino decay or $W$ are on-shell. The
signal is then underestimated if only on-shell effective theory approach is
taken in simulation of signal and the real bound on squark/gluino should be
more stringent.
