Searches for the $t^{\mathrm{\prime }}$ of a fourth family

We study the detection of the $t^{\mathrm{\prime }}$ of a fourth family during the early running of LHC with 7 TeV collision energy and 1 fb${}^{-1}$ integrated luminosity. By use of a neural network we show that it is feasible to search for the $t^{\mathrm{\prime }}$ even with a mass close to the unitarity upper bound, which is in the 500 to 600 GeV range. We also present results for the Tevatron with $10 ,, $\text{fb}$^{-1}$. In both cases the search for a fourth family quark doublet can be significantly enhanced if one incorporates the contribution that the $b^{\mathrm{\prime }}$ can make to a $t^{\mathrm{\prime }}$-like signal. Thus the bound on the mass of a degenerate quark doublet should be stronger than the bounds obtained by treating $t^{\mathrm{\prime }}$ and $b^{\mathrm{\prime }}$ in isolation.