Search for a Heavy Top-like Quark in the Dilepton Final State in pp Collisions at 7~TeV

The results of a search for pair production of a heavy top-like $t'$ quark in the decay mode $t' \bar{t'} \to bW^{+} \bar{b}W^{-} \to b \ell^{+} \nu \: \bar{b} \ell^{-} \bar{\nu}$ are presented. The search is performed in a data sample corresponding to a total integrated luminosity of 1.14~fb$^{-1}$ of $pp$ collisions at a centre-of-mass energy of 7~TeV, collected by the CMS experiment at the LHC. The observed number of events agrees with the standard model prediction, and no evidence of $t' \bar{t'}$ production is found. Upper limits on the production cross section as a function of $t'$ mass are presented. A $t'$ with a mass below 422~\GeVcc\ is excluded at the 95\%~C.L.