# ${\boldsymbol {\boldsymbol t}}$-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.

# ${{\boldsymbol t}}$-Quark Yukawa Coupling from ${{\boldsymbol t}}{{\overline{\boldsymbol t}}}$ Kinematic Distributions in ${{\boldsymbol p}}{{\boldsymbol p}}$ Collisions INSPIRE search

The ratio of ${{\mathit t}}$-quark Yukawa coupling to its standard model predicted value.
VALUE DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$1.07$ ${}^{+0.34}_{-0.43}$ 1
 2019 BY
CMS ${{\mathit \ell}}$+jets, ${{\mathit t}}{{\overline{\mathit t}}}$ threshold
1  SIRUNYAN 2019BY based on 35.8 ${\mathrm {fb}}{}^{-1}$ of data at $\sqrt {s }$ = 13 TeV. Experimental sensitivity is enhanced in the low $\mathit M_{ {{\mathit t}} {{\overline{\mathit t}}} }$ region. The distributions of $\mathit M_{ {{\mathit t}} {{\overline{\mathit t}}} }$, $\vert \mathit y_{t}$ $−$ $\mathit y_{{{\overline{\mathit t}}}}\vert$, and the number of reconstructed jets are compared with predictions by different Yukawa couplings which include NNLO QCD and NLO EW corrections.
References:
 SIRUNYAN 2019BY
PR D100 072007 Measurement of the top quark Yukawa coupling from $\mathrm{t\bar{t}}$ kinematic distributions in the lepton+jets final state in proton-proton collisions at $\sqrt{s} =$ 13 TeV