Measurement of the inclusive cross section of single top quark production in the $t$ channel at $\sqrt{s} = 13\,\mathrm{TeV}$

The $t$ channel single top quark production cross section is measured in proton proton collisions at $13\,\mathrm{TeV}$ with the CMS detector at the CERN LHC. The analyzed data correspond to an integrated luminosity of $2.3\,\mathrm{fb}^{-1}$. After a selection optimized for the $t$ channel single top quark production with a muon+jets signature in the final state, several kinematic variables are combined into one multivariate discriminator optimized to separate signal from background events. A fit to the distribution of the discriminating variable yields cross sections of $\sigma_{t\textrm{-ch.,t}} = 141.5 \pm 6.7\,{\rm(stat.)} \pm 9.4\,{\rm(exp.)}\,^{+19.3}_{-19.6}\,{\rm(theo.)}\pm 3.8\,{\rm(lumi.)}\,{\rm pb}$ and $\sigma_{t\textrm{-ch.,}\bar{\textrm{t}}} = 81.0 \pm 6.2\,{\rm(stat.)} \pm 8.1\,{\rm(exp.)}\,^{+10.9}_{-10.9}\,{\rm(theo.)}\pm 2.2\,{\rm(lumi.)}\,{\rm pb}$ for the production of single top quarks and single top anti-quarks, respectively. From the measured inclusive cross section, $\sigma_{t\textrm{-ch.}} = 227.8 \pm 9.1\,{\rm(stat.)} \pm 14.0\,{\rm(exp.)}\,^{+28.7}_{-27.7}\,{\rm(theo.)}\pm 6.2\,{\rm(lumi.)}\,{\rm pb}$, and the predicted value the CKM matrix element $V_{\mathrm{tb}}$ is calculated to be $|V_{\mathrm{tb}}| = 1.02 \pm 0.07\,{\rm(exp.)}\pm 0.02\,{\rm(theo.)}$. All results are in agreement with the standard model predictions. $$\textit{This document has been revised with respect to the version dated March 25, 2016.}$$