Abstract
The first observation of top quark production in proton-nucleus collisions is reported using proton-lead data collected by the CMS experiment at the CERN LHC at a nucleon-nucleon center-of-mass energy of $\sqrt{s_{NN}}$ = 8.16 TeV. The measurement is performed using events with exactly one isolated electron or muon candidate and at least four jets. The data sample corresponds to an integrated luminosity of 174 $nb^{−1}$. The significance of the $t\overline{t}$ signal against the background-only hypothesis is above 5 standard deviations. The measured cross section is $\sigma_{t\overline{t}} = 45±8 nb$, consistent with predictions from perturbative quantum chromodynamics.
CMS Collaboration