skip to main content


Title: Measurements of top quark properties in top pair production and decay at the LHC using the CMS detector

Measurements are presented of the properties of top quarks in pair production and decay from proton-proton collisions at the LHC. The data were collected at centre-of-mass energies of 7 and 8 TeV by the CMS experiment during the years 2011 and 2012. The top quark-antiquark charge asymmetry is measured using the difference of the absolute rapidities of the reconstructed top and anti-top kinematics, as well as from distributions of the top quark decay products. The measurements are performed in the decay channels of the tt¯ pair into both one and two leptons in the final state. The polarization of top quarks and top pair spin correlations are measured from the angular distributions of top quark decay products. The W-boson helicity fractions and angular asymmetries are extracted and limits on anomalous contributions to the Wtb vertex are determined. The flavor content in top-quark pair events is measured using the fraction of top quarks decaying into a W-boson and a b -quark relative to all top quark decays, R=B(t→Wb)/B(t→Wq) , and the result is used to determine the CKM matrix element Vtb as well as the width of the top quark resonance. Finally, all of the results are found to be inmore » good agreement with standard model predictions.« less
  1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 2405-6014; 1467820
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nuclear and Particle Physics Proceedings
Additional Journal Information:
Journal Volume: 273-275; Journal Issue: C; Journal ID: ISSN 2405-6014
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
CMS Collaboration
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; LHC; CMS; top quark; charge asymmetry; spin correlations; polarization
OSTI Identifier: