Measurement of the W-boson mass in top-quark decays from tt-bar production in lepton and jets events in proton-proton collisions

A measurement is performed of the mass of the W-boson produced in top quarks events. CMS data was used and simulation samples from previous top studies in the CERN CMS group to develop this new analysis method. The measurement is based on $13 TeV$ proton-proton collision data corresponding to and integrated luminosity of $35.9 fb^{-1}$, the measured mass of the W-boson was found to be equal $m_w=80.317\pm0.072 \text{(stat)}\pm1.315{(syst)}\pm1.317{(Total)} GeV$ to and the measurement of the mass difference between the W+and W- bosons yields $m_{W+}- m_{W-}=0.008\pm0.149{(stat)}\pm0.488{(syst)}\pm0.509 {(Total)} GeV$ . The results where compared with PDG, Tevatron's, LEP and ATLAS (2017).