2020/02/21 by Defranchis, Matteo M.
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.2002.09288
Measurements of the top quark-antiquark pair production cross section, σ_\mathrmtt, can be used to constrain the strong coupling constant, αS, the top quark mass, mt, and the parton distribution functions (PDFs). In this poster, the two most recent relevant results published by the CMS Collaboration are presented. The analyses are performed using proton-proton collision data at a centre-of-mass energy of 13 TeV recorded by the CMS detector at the CERN LHC in 2016, corresponding to an integrated luminosity of 35.9~\mathrmfb-1. In the first one, αS and mt are extracted independently from a measurement of the inclusive σ_\mathrmtt, using next-to-next-to-leading order theoretical predictions. In the second, a measurement of the normalized triple-differential \mathrmtt cross section is performed; the result is then used together with HERA deep-inelastic scattering data to perform a simultaneous determination of αS, mt, and the PDFs, at next-to-leading order. As a result, the uncertainty in the gluon PDF and its correlation with αS are significantly reduced at high parton momentum fraction, the kinematic range probed by \mathrmtt production. The result also yields the most precise determination of the top quark pole mass, to date.