CMS-PAS-TOP-17-023

CMS-PAS-TOP-17-023
Measurement of differential cross sections and charge ratios for $t$-channel single top quark production at 13 TeV
CMS Collaboration
March 2019

Abstract: A measurement is presented of differential cross sections for $t$-channel single top quark production in proton-proton collisions at a centre-of-mass energy of 13 TeV by the CMS experiment at the LHC. Events containing single muons or electrons and two or three jets are analysed, corresponding to an integrated luminosity of 36 fb$^{-1}$. The cross section is measured as a function of the top quark transverse momentum, rapidity, and polarization angle, the charged lepton transverse momentum and rapidity, and the transverse momentum of the W boson from the top quark decay. In addition, the charge ratio, defined as the ratio of the single top quark cross section to the sum of the single top quark and antiquark cross sections, is measured differentially as a function of the top quark, charged lepton, and W boson kinematic observables. The results are found to be in agreement with predictions using various next-to-leading order event generators and various sets of parton distribution functions. Additionally, the spin asymmetry, sensitive to the top quark polarisation, is determined from the differential distribution of the polarisation angle at parton level to be 0.439 $\pm$ 0.062, in agreement with the standard model prediction using the POWHEG event generator at next-to-leading order.
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, EPJC 80 (2020) 370. The superseded preliminary plots can be found here.

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