The search for charginos and neutralinos with ATLAS detector at LHC

We report hereafter on particle level simulations done in the framework of the MSSM to search for the X-bar+-1 X-bar02 -> 3 l + X at LHC using a parametrized response of the ATLAS detector. We first establish the observability of an excess of trilepton events with respect to the SM predictions. Then we show the particular process cited above can be extracted from this trilepton excess. We propose an original method to evaluate the MSSM main parameter, namely mg-bar, using the above signal. And finally we apply the latest to also approach the charginos and neutralinos masses. (author)