Searches for Charginos and Neutralinos in $e^{+}e^{-}$ collisions at $\sqrt{s} \simeq$ 183 GeV and the limit on the lightest neutralino

Charginos and neutralinos of the MSSM have been searched for in the data collected by the ALEPH detector at centre-of-mass energies close to 183~GeV. No evidence of a signal is found and chargino and neutralino production is excluded for masses close to the kinematic limit when the slepton masses are large. The effect of light sleptons on chargino and neutralino limits is investigated.