Search for standard model four top quark production at 8 TeV in the lepton + jets channel

A search for four top quark production in the single lepton plus jets channel is presented. The dataset used corresponds to an integrated luminosity of 19.6 fb$^{-1}$ at $\sqrt{s}$= 8 TeV recorded by the CMS experiment in 2012. A combination of kinematic reconstruction and multivariate techniques is used to distinguish between signal and backgrounds. No excess of events over the standard model expectation is observed. Upper limits on the cross section of standard model four top quark production of $42^{+18}_{-13}$ fb (expected) and 63 fb (observed) at 95 \% CL are calculated.