The LHC physics program goes far beyond the discovery of the Higgs-like boson, highlighted in Moriond 2013. Besides many novel analyses, the CMS experiment presented for the first time a measurement of the W-halicity fractions in singletop event topology in this conference. The analysis follows the LHC physics strategy in search for new physics beyond the Standard Model (SM) where the precision measurements and model independent data analyses play a crucial role. The study of top quark allows the investigation of new interactions at higher energies that may manifest themselves in the form of effective couplings in the SM fermions. The heaviest known fermion of the SM decays almost exclusively to a b-quark and a W-boson. The polarization of the W-boson from top quark is sensitive to non-SM tWb couplings. We performed a measurement of the W-boson helicity fractions in single-top events topology in muon+jets final state using LHC pp collisions at 7 TeV and 8 TeV center-of-mass energies. The datasets are collected by the CMS detector during 2011 (A) and 2012 (A+B) runs, respectively corresponding to an integrated luminosity of 1.14 fb−1 and 5.3 fb−1. The combination of the two measurements yields FL = 0.293 ± 0.069(stat.) ± 0.030(syst.), F0 = 0.713 ± 0.114(stat.) ± 0.023(syst.) and FR = −0.006 ± 0.057(stat.) ± 0.027(syst.). The

measured polarizations are used to set limits on tWb anomalous couplings.

Figure 1: Combined results from 8 TeV and 7 TeV center-of-mass energies for the W-helicity fractions in single-top event topology. Within the uncertainties, results are consistent with the SM

predictions and the results from other measurements.