Search for an excited quark decaying to a top quark plus gluon.

We perform a search for a pair-produced-excited top quark, t*, that decays exclusively to a top quark and a gluon using data collected by the CMS detector from pp collisions at $\sqrt{s}$ = 8 TeV. The search is performed using events consistent with the semi-leptonic decay of the t*t*system, that is events having a single isolated muon or electron, missing energy, and at least six well-reconstructed jets, one of which must be identified as originating from the fragmentation of a b quark. The data analyzed corresponds to an integrated luminosity of 19.6 fb$^{-1}$ in both muon and electron channel. No significant excess over expectations is observed and we set a lower limit is on a t*-quark mass at 95\% confidence level.