Supersymmetric W Boson Decays as a Means to Search for Charginos and Neutralinos
Abstract
If the sneutrino mass is below the chargino mass, the dominant decay mode of the lightest chargino is via a two-body decay channel $\chi^{\pm}_1 \ra \tilde{\nu} + l^{\pm}$. Sneutrinos are invisible in
R
-parity conserving supersymmetric models and, if the mass gap
m(
χ
±
1
)−m(
ν
~
)
is sufficiently small, the soft decay lepton may escape detection leading to invisible chargino decays. This ``blind spot'' of the supersymmetry parameter space would jeopardize the chargino search at LEP2. We point out that such a scenario can be tested by searching for single
W
events in $e^+e^- \ra W^+W^-$, with one
W
boson decaying to visible leptons or quark jets, and the second
W
boson decaying to invisible charginos and neutralinos.