${\mathit {\mathit t}}$-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.

${{\mathit F}_{{{0}}}}$

INSPIRE   PDGID:
Q007TV0
VALUE DOCUMENT ID TECN  COMMENT
$\bf{ 0.693 \pm0.013}$ OUR AVERAGE
$0.693$ $\pm0.009$ $\pm0.011$ 1
AAD
2020Y
 LHC ATLAS+CMS combined
$0.726$ $\pm0.066$ $\pm0.067$ 2
AALTONEN
2013D
 CDF ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
$0.682$ $\pm0.030$ $\pm0.033$ 3
CHATRCHYAN
2013BH
 CMS ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
$0.67$ $\pm0.07$ 4
AAD
2012BG
 ATLS ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
$0.722$ $\pm0.062$ $\pm0.052$ 5
AALTONEN
2012Z
 TEVA ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
$0.669$ $\pm0.078$ $\pm0.065$ 6
ABAZOV
2011C
 D0 ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
$0.91$ $\pm0.37$ $\pm0.13$ 7
AFFOLDER
2000B
 CDF ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
• • We do not use the following data for averages, fits, limits, etc. • •
$0.70$ $\pm0.05$ 8
AABOUD
2017BB
 ATLS ${{\mathit F}_{{{0}}}}$ = 1 $−$ ${{\mathit f}_{{{1}}}}$, Repl by AAD 2020Y
$0.681$ $\pm0.012$ $\pm0.023$ 9
KHACHATRYAN
2016BU
 CMS ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$), Repl by AAD 2020Y
$0.70$ $\pm0.07$ $\pm0.04$ 10
AALTONEN
2010Q
 CDF Repl. by AALTONEN 2012Z
$0.62$ $\pm0.10$ $\pm0.05$ 11
AALTONEN
2009Q
 CDF Repl. by AALTONEN 2010Q
$0.425$ $\pm0.166$ $\pm0.102$ 12
ABAZOV
2008B
 D0 Repl. by ABAZOV 2011C
$0.85$ ${}^{+0.15}_{-0.22}$ $\pm0.06$ 13
ABULENCIA
2007I
 CDF ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
$0.74$ ${}^{+0.22}_{-0.34}$ 14
ABULENCIA
2006U
 CDF ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
$0.56$ $\pm0.31$ 15
ABAZOV
2005G
 D0 ${{\mathit F}_{{{0}}}}$ = B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}_{{{0}}}}{{\mathit b}}$)
1  AAD 2020Y based on about 20 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8 TeV for each experiment. The first error stands for the sum of the statistical and background uncertainties, and the second error for the remaining systematic uncertainties. The measurements used events with one lepton and different jet multiplicities in the final state. The result is consistent with the NNLO SM prediction of $0.687$ $\pm0.005$ for ${\mathit m}_{{{\mathit t}}}$ = $172.8$ $\pm1.3$ GeV.
2  Based on 8.7 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96 TeV using ${{\mathit t}}{{\overline{\mathit t}}}$ events with ${{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}$4 jets(${}\geq{}$1 ${{\mathit b}}$), and under the constraint F$_{0}$ + F$_{+}$ + F$_{-}$ = 1. The statstical errors of F$_{0}$ and F$_{+}$ are correlated with correlation coefficient $\rho (F_{0},F_{+}$) = $-0.69$.
3  Based on 5.0 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. CHATRCHYAN 2013BH studied events with large $\not E_T$ and ${{\mathit \ell}}$ +${}\geq{}$4 jets using a constrained kinematic fit.
4  Based on 1.04 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. AAD 2012BG studied events with large $\not E_T$ and either ${{\mathit \ell}}$ +${}\geq{}$4j or ${{\mathit \ell}}{{\mathit \ell}}$ +${}\geq{}$2j. The uncertainties are not independent, $\rho ({{\mathit F}_{{{0}}}},{{\mathit F}_{{{-}}}}$) = $-0.96$.
5  Based on 2.7 and 5.1 fb${}^{-1}$ of CDF data in ${{\mathit \ell}}$ + jets and dilepton channels, and 5.4 fb${}^{-1}$ of D0 data in ${{\mathit \ell}}$ + jets and dilepton channels. ${{\mathit F}_{{{0}}}}$ = $0.682$ $\pm0.035$ $\pm0.046$ if ${{\mathit F}_{{{+}}}}$ = 0.0017(1), while ${{\mathit F}_{{{+}}}}$ = $-0.015$ $\pm0.018$ $\pm0.030$ if ${{\mathit F}_{{{0}}}}$ = 0.688(4), where the assumed fixed values are the SM prediction for ${\mathit m}_{{{\mathit t}}}$ = $173.3$ $\pm1.1$ GeV and ${\mathit m}_{{{\mathit W}}}$ = $80.399$ $\pm0.023$ GeV.
6  Results are based on 5.4 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at 1.96 TeV, including those of ABAZOV 2008B. Under the SM constraint of ${{\mathit f}_{{{0}}}}$ = 0.698 (for ${\mathit m}_{{{\mathit t}}}$ = 173.3 GeV, ${\mathit m}_{{{\mathit W}}}$ = 80.399 GeV), ${{\mathit f}_{{{+}}}}$ = $0.010$ $\pm0.022$ $\pm0.030$ is obtained.
7  AFFOLDER 2000B studied the angular distribution of leptonic decays of ${{\mathit W}}$ bosons in ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$ events. The ratio $\mathit F_{0}$ is the fraction of the helicity zero (longitudinal) ${{\mathit W}}~$bosons in the decaying top quark rest frame. B( ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}}_{+}$ ${{\mathit b}}$) is the fraction of positive helicity (right-handed) positive charge ${{\mathit W}}~$bosons in the top quark decays. It is obtained by assuming the Standard Model value of $\mathit F_{0}$.
8  AABOUD 2017BB based on 20.2 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8 TeV. Triple-differential decay rate of top quark in the ${{\mathit t}}$-channel single-top production is used to simultaneously determine five generalized ${{\mathit W}}{{\mathit t}}{{\mathit b}}$ couplings as well as the top polarization. No assumption is made for the other couplings. See this paper for constraints on other couplings not included here. The paper reported ${{\mathit f}_{{{1}}}}$, and we converted it to ${{\mathit F}_{{{0}}}}$.
9  KHACHATRYAN 2016BU based on 19.8 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8 TeV using ${{\mathit t}}{{\overline{\mathit t}}}$ events with ${{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}$4 jets(${}\geq{}$2 ${{\mathit b}}$). The errors of ${{\mathit F}_{{{0}}}}$ and ${{\mathit F}_{{{-}}}}$ are correlated with a correlation coefficient $\rho ({{\mathit F}_{{{0}}}}$, ${{\mathit F}_{{{-}}}}$) = $-0.87$. The result is consistent with the NNLO SM prediction of $0.687$ $\pm0.005$ for ${\mathit m}_{{{\mathit t}}}$ = $172.8$ $\pm1.3$ GeV.
10  Results are based on 2.7 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96 TeV. ${{\mathit F}_{{{0}}}}$ result is obtained by assuming ${{\mathit F}_{{{+}}}}$ = 0, while ${{\mathit F}_{{{+}}}}$ result is obtained for ${{\mathit F}_{{{0}}}}$ = 0.70, the SM value. Model independent fits for the two fractions give ${{\mathit F}_{{{0}}}}$ = $0.88$ $\pm0.11$ $\pm0.06$ and ${{\mathit F}_{{{+}}}}$ = $-0.15$ $\pm0.07$ $\pm0.06$ with correlation coefficient of $-0.59$. The results are for ${\mathit m}_{{{\mathit t}}}$ = 175 GeV.
11  Results are based on 1.9 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96 TeV. ${{\mathit F}_{{{0}}}}$ result is obtained assuming ${{\mathit F}_{{{+}}}}$ = 0, while ${{\mathit F}_{{{+}}}}$ result is obtained for ${{\mathit F}_{{{0}}}}$ = 0.70, the SM values. Model independent fits for the two fractions give ${{\mathit F}_{{{0}}}}$ = $0.66$ $\pm0.16$ $\pm0.05$ and ${{\mathit F}_{{{+}}}}$ = $-0.03$ $\pm0.06$ $\pm0.03$.
12  Based on 1 fb${}^{-1}$ at $\sqrt {s }$ = 1.96 TeV.
13  Based on 318 pb${}^{-1}$ of data at $\sqrt {s }$ = 1.96 TeV.
14  Based on 200 pb${}^{-1}$ of data at $\sqrt {s }$ = 1.96 TeV. ${{\mathit t}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$ $\rightarrow$ ${{\mathit \ell}}{{\mathit \nu}}{{\mathit b}}$ (${{\mathit \ell}}$ = ${{\mathit e}}$ or ${{\mathit \mu}}$). The errors are stat + syst.
15  ABAZOV 2005G studied the angular distribution of leptonic decays of ${{\mathit W}}$ bosons in ${{\mathit t}}{{\overline{\mathit t}}}$ candidate events with lepton + jets final states, and obtained the fraction of longitudinally polarized ${{\mathit W}}$ under the constraint of no right-handed current, ${{\mathit F}_{{{+}}}}$ = 0. Based on 125 pb${}^{-1}$ of data at $\sqrt {s }$ = 1.8 TeV.
References