<p>The results of a search for pair production of a heavy, top-like quark, t<sup>′</sup>, in the decay mode <a></a> are presented. The search is performed with a data sample corresponding to an integrated luminosity of 5.0 fb<sup>−1</sup> in pp collisions at a center-of-mass energy of 7 TeV, collected by the CMS experiment at the LHC. The observed number of events agrees with the expectation from standard model processes, and no evidence of <a></a> production is found. Upper limits on the production cross section as a function of t<sup>′</sup> mass are presented, and t<sup>′</sup> masses below 557 GeV/c<sup>2</sup> are excluded at the 95% confidence level.</p>