${\boldsymbol {\boldsymbol t}}$-quark EW Couplings

${{\mathit W}}$ helicity fractions in top decays. ${{\mathit F}_{{0}}}$ is the fraction of longitudinal and ${{\mathit F}_{{+}}}$ the fraction of right-handed ${{\mathit W}}$ bosons. ${{\mathit F}_{{{V+A}}}}$ is the fraction of $\mathit V+\mathit A$ current in top decays. The effective Lagrangian (cited by ABAZOV 2008AI) has terms f${}^{L}_{1}$ and f${}^{R}_{1}$ for $\mathit V−\mathit A$ and $\mathit V+\mathit A$ couplings, f${}^{L}_{2}$ and f${}^{R}_{2}$ for tensor couplings with b$_{R}$ and b$_{L}$ respectively.

$\vert$f$_{LV}V_{tb}\vert$ INSPIRE search

Assumed that the top-quark-related CKM matrix elements obey the relation $\vert V_{td}\vert$, $\vert V_{ts}\vert {}\ll\vert V_{tb}\vert$ and a form factor f$_{LV}$ is determined for each production mode and centre-of-mass energy.
VALUE DOCUMENT ID TECN  COMMENT
$1.02$ $\pm0.04$ $\pm0.02$ 1
 2019 R
LHC ATLAS + CMS at 7, 8 TeV
1  The combination of single-top production cross-section measurements in the ${{\mathit t}}$-channel, ${{\mathit t}}{{\mathit W}}$ , and ${{\mathit s}}$-channel production modes from ATLAS and CMS at $\sqrt {s }$ = 7 and 8 TeV.
References:
 AABOUD 2019R
JHEP 1905 088 Combinations of single-top-quark production cross-section measurements and |f$_{LV}$V$_{tb}$| determinations at $\sqrt{s}$ = 7 and 8 TeV with the ATLAS and CMS experiments