Extraction of CKM matrix elements in single top quark t-channel production in pp collisions at sqrt(s) = 13 TeV, with CMS

<!--HTML--><p><span><span>A model-independent&nbsp;extraction of the modulus of the Cabibbo–&nbsp;Kobayashi–Maskawa matrix elements Vtb, Vtd, and Vts,&nbsp;is presented for&nbsp;the first time using an event sample enriched in single top quark&nbsp;t-channel events. The analysis uses&nbsp;proton-proton collisions data from&nbsp;the LHC, collected during 2016 with the CMS experiment, at a&nbsp;centre-of-mass energy of&nbsp;13 TeV, corresponding to an integrated&nbsp;luminosity of 35.9 fb−1. Processes directly sensitive to the matrix&nbsp;elements Vtb,&nbsp;Vtd, and Vts are considered in both the production and&nbsp;decay vertices of the top quark in single top quark t-channel&nbsp;production, as well as in the background processes containing top&nbsp;quarks. In the standard model hypothesis of CKM&nbsp;unitarity, a lower limit&nbsp;of |Vtb| &gt; 0.971 is measured&nbsp;at the 95% confidence level. Several beyond-the standard model&nbsp;possibilities are considered, and by releasing all constraints between&nbsp;the involved parameters, the values |Vtb| = 0.988 ±&nbsp;0.024, and |Vtd|2 +&nbsp;|Vts|2 = 0.06 ± 0.06 are measured.</span></span></p>