Measurement of the Jet Mass Distribution and Top Quark Mass in Hadronic Decays of Boosted Top Quarks in pp Collisions at √s = 13 TeV

A. M. Sirunyan, A. Tumasyan, W. Adam, F. Ambrogi, T. Bergauer, J. Brandstetter, M. Dragicevic, J. Erö, A. Escalante Del Valle, M. Flechl, R. Frühwirth, M. Jeitler (+2307 others)
2020
A measurement is reported of the jet mass distribution in hadronic decays of boosted top quarks produced in pp collisions at ffiffi ffi s p ¼ 13 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb −1 . The measurement is performed in the lepton þ jets channel of tt events, where the lepton is an electron or muon. The products of the hadronic top quark decay t → bW → bqq 0 are reconstructed as a single jet with transverse momentum
more » ... rger than 400 GeV. The tt cross section as a function of the jet mass is unfolded at the particle level and used to extract a value of the top quark mass of 172.6 AE 2.5 GeV. A novel jet reconstruction technique is used for the first time at the LHC, which improves the precision by a factor of 3 relative to an earlier measurement. This highlights the potential of measurements using boosted top quarks, where the new technique will enable future precision measurements.
doi:10.5445/ir/1000119669 fatcat:edufhdrydzapxh2pl2742qlzjy