Bounds on "charginos nearly degenerate with the lightest neutralino"   mass from precision measurements
  Though LEP II direct searches still cannot exclude a chargino nearly degenerate with the lightest neutralino if its mass is only slightly above half of the Z boson mass and the sneutrino is light, it can be excluded indirectly analyzing precision data. In this particular limit simple analytical formulas for oblique electroweak radiative corrections are presented. 
M. Maltoni