We study how the properties of the four neutralino states , \chi _ { i } ( i = 1 , 2 , 3 , 4 ) , can be investigated at the Large Hadron Collider ( LHC ) , in the case when the lightest one , \chi _ { 1 } , has a mass m _ { \chi } \mathrel { \mathop { \kern 0.0 pt \hbox to 0.0 pt { \raise 0.86 pt \hbox { $ < $ } } } % \lower 3.87 pt \hbox { \kern - 1.9 pt$ \sim$ } } 50 GeV and is stable .
This situation arises naturally in supersymmetric models where gaugino masses are not unified at a Grand Unified ( GUT ) scale and R-parity is conserved .
The main features of these neutralino states are established by analytical and numerical analyses , and two scenarios are singled out on the basis of the cosmological properties required for the relic neutralinos .
Signals expected at LHC are discussed through the main chain processes started by a squark , produced in the initial proton-proton scattering .
We motivate the selection of some convenient benchmarks , in the light of the spectroscopical properties ( mass spectrum and transitions ) of the four neutralino states .
Branching ratios and the expected total number of events are derived in the various benchmarks , and their relevance for experimental determination of neutralino properties is finally discussed .