${{\mathit t}}$-quark Polarization in Single Top Events in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 13 TeV

INSPIRE   PDGID:
Q007A04
VALUE DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$0.01$ $\pm0.18$ 1
AAD
2022Z
 ATLS ${{\mathit P}}_{{{\mathit x}^{\,'}}}$ (${{\mathit t}}$, transverse component)
$-0.029$ $\pm0.027$ 1
AAD
2022Z
 ATLS ${{\mathit P}}_{{{\mathit y}^{\,'}}}$ (${{\mathit t}}$, normal component)
$0.91$ $\pm0.10$ 1
AAD
2022Z
 ATLS ${{\mathit P}}_{{{\mathit z}^{\,'}}}$ (${{\mathit t}}$, parallel component)
$-0.02$ $\pm0.20$ 1
AAD
2022Z
 ATLS ${{\mathit P}}_{{{\mathit x}^{\,'}}}$ (${{\overline{\mathit t}}}$, transverse component)
$-0.007$ $\pm0.051$ 1
AAD
2022Z
 ATLS ${{\mathit P}}_{{{\mathit y}^{\,'}}}$ (${{\overline{\mathit t}}}$, normal component)
$-0.79$ $\pm0.16$ 1
AAD
2022Z
 ATLS ${{\mathit P}}_{{{\mathit z}^{\,'}}}$ (${{\overline{\mathit t}}}$, parallel component)
$0.440$ $\pm0.070$ 2
SIRUNYAN
2020R
 CMS (${{\mathit \alpha}_{{{{\mathit \ell}}}}}\mathit P$)/2; t-channel
1  AAD 2022Z based on 139 fb${}^{-1}$ of data. Three components of ${{\mathit t}}$ or ${{\overline{\mathit t}}}$ polarization vector (defined in the ${{\mathit t}}$ or ${{\overline{\mathit t}}}$ rest frame) are measured in $\mathit t$-channel single top production using ${{\mathit \ell}}$ momentum distribution in the ${{\mathit \ell}}$ + $\not E_T$ + 2j (with 1 of them ${{\mathit b}}$-jet) channel. The measured values are in agreement with NNLO SM prediction. Constraints on the Wilson coefficients of SMEFT are obtained as -0.9 $<$ ${{\mathit C}_{{tW}}}$ $<$ 1.4 and -0.8 $<$ ${{\mathit C}_{{itW}}}$ $<$ 0.2.
2  SIRUNYAN 2020R based on 36.1 fb${}^{-1}$ of data. Differential cross sections for $\mathit t$-channel single top production are measured using 1${{\mathit \ell}}$ + 2,3-jet mode and found to be in good agreement with SM predictions. The value is the top spin asymmetry, given by 1/2 of the spin analyzing power ${{\mathit \alpha}_{{{{\mathit \ell}}}}}$ (=1 at LO of SM) times the top polarization $\mathit P$, where the spin axis is defined as the direction of the spectator quark in the top rest frame at the parton level. It is in good agreement with the NLO SM prediction of 0.436.
References:
AAD 2022Z
JHEP 2211 040 Measurement of the polarisation of single top quarks and antiquarks produced in the t-channel at $ \sqrt{s} $ = 13 TeV and bounds on the tWb dipole operator from the ATLAS experiment
SIRUNYAN 2020R
EPJ C80 370 Measurement of differential cross sections and charge ratios for t-channel single top quark production in proton?proton collisions at $\sqrt{s}=13\,\text {Te}\text {V}$