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

Özet

A measurement of the top quark–antiquark pair production cross section ?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± ? ?, ? + ? ?, e+e?) are selected and the cross section is measured from a likelihood fit. For a top quark mass parameter in the simulation of mMC t = 172.5GeV the fit yields a measured cross section ?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 mMC t = 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 heoretical prediction, to determine the top quark mass and to extract a value of the strong coupling constant with different sets of parton distribution functions.

Açıklama

Anahtar Kelimeler

High Energy Physics - Experiment

Kaynak

WoS Q Değeri

Q1

Scopus Q Değeri

Q1

Cilt

Sayı

Künye

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