Search for CP violation in top-pair events with lepton+jets channel at sqrt(s) = 8TeV

We present the first measurement at the LHC of CP-violation asymmetries in $t \bar t$ events based on the T-odd triple product correlations. The analyzed data are collected by the CMS experiment from pp collisions at a center-of-mass energy $\sqrt{s} = 8$ TeV and correspond to an integrated luminosity of $19.7~{\rm fb^{-1}}$. The T-odd observables are measured using the linearly independent four-momentum vectors associated with the top quark production and decay. The measured asymmetries show no evidence for CP-violation effects in $t \bar t$ events, in agreement with the standard model prediction.