  Searches for signatures of new physics in top anti-top events at the LHC
require efficient reconstruction of top quarks with a broad range of transverse
momenta. Three new reconstruction schemes are developed to deal with the large
variety of top decay topologies. Their performance on the lepton + jets final
state is evaluated using a detailed simulation of signal and background
processes. Compared to previous ATLAS studies, a much improved reconstruction
efficiency is found over a large top anti-top invariant mass range. As a
consequence, even in the earliest phase of the experiment, ATLAS is expected to
significantly extend the mass reach of existing searches.
