Measurement of CKM matrix elements in single top quark $t$-channel production in proton-proton collisions at $\sqrt{s} = $ 13 TeV
Journal
Phys. Lett. B 808 (2020) 135609
Journal Volume
808
Date Issued
2020-04-26
Author(s)
Abstract
The first direct, model-independent measurement is presented of the modulus
of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements $|V_\mathrm{tb}|$,
$|V_\mathrm{td}|$, and $|V_\mathrm{ts}|$, in final states enriched in single
top quark $t$-channel events. The analysis uses proton-proton collision data
from the LHC, collected during 2016 by the CMS experiment, at a centre-of-mass
energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$.
Processes directly sensitive to these matrix elements are considered at both
the production and decay vertices of the top quark. In the standard model
hypothesis of CKM unitarity, a lower limit of $|V_\mathrm{tb}|$ $>$ 0.970 is
measured at the 95% confidence level. Several theories beyond the standard
model are considered, and by releasing all constraints among the involved
parameters, the values $|V_\mathrm{tb}| =$ 0.988 $\pm$ 0.024, and
$|V_\mathrm{td}|^2 + |V_\mathrm{ts}|^2 =$ 0.06 $\pm$ 0.06, where the
uncertainties include both statistical and systematic components, are measured.
Subjects
CKM matrix | CMS | Physics | Top quark; High Energy Physics - Experiment; High Energy Physics - Experiment
SDGs
Description
Replaced with the published version. Added the journal reference and
the DOI. All the figures and tables can be found at
http://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-17-012
(CMS Public Pages)
the DOI. All the figures and tables can be found at
http://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-17-012
(CMS Public Pages)
Type
journal article