Measurement of the tt production cross section, the top quark mass, and the strong coupling constant using dilepton events in pp collisions at √s = 13TeV

Authors

CMS Collaboration, CMS CollaborationFollow

Date of this Version

2019

Citation

Eur. Phys. J. C (2019) 79:368

Comments

© CERN for the benefit of the CMS collaboration 2019

https://doi.org/10.1140/epjc/s10052-019-6863-8

Abstract

A measurement of the top quark–antiquark pair production cross section σ_tt in proton–proton collisions at a centre-of-mass energy of 13 TeV is presented. The data correspond to an integrated luminosity of 35.9 fb⁻¹, recorded by the CMS experiment at the CERN LHC in 2016. Dilepton events (e^± μ^∓, μ⁺ μ⁻, e⁺e⁻) are selected and the cross section is measured from a likelihood fit. For a top quark mass parameter in the simulation of m_t^MC = 172.5GeV the fit yields a measured cross section σ_tt = 803 ± 2 (stat) ± 25 (syst) ± 20 (lumi) pb, in agreement with the expectation from the standard model calculation at next-to-next-toleading order. A simultaneous fit of the cross section and the top quark mass parameter in the powheg simulation is performed. The measured value of m_t^MC = 172.33 ± 0.14 (stat) +0.66 −0.72 (syst) GeV is in good agreement with previous measurements. The resulting cross section is used, together with the theoretical prediction, to determine the top quark mass and to extract a value of the strong coupling constant with different sets of parton distribution functions.