We evaluate the discovery reach of the ATLAS experiment for down type
isosinglet quarks, D, using both their neutral and charged decay channels,
namely the process pp→DDˉ+X with subsequent decays resulting in
2ℓ+2j+ETmiss, 3ℓ+2j+ETmiss and 2ℓ+4j final states.
The integrated luminosity required for observation of a heavy quark is
estimated for a mass range between 600 and 1000 GeV using the combination of
results from different search channels.Comment: 12 page