  A new method of solving the hierarchy problem in the SM has been proposed.
This method leads to the so-called "Little Higgs" models. The ATLAS experiment
at LHC has undertaken studies of the new particles predicted by these model: a
heavy top quark, heavy gauge bosons and additional Higgs bosons. Simulations of
their decays have been carried out. The sensitivity of the ATLAS experiment to
discover these new particles is discussed.
