Studying the $Wtb$ vertex structure using recent LHC results

TL;DR

This paper analyzes the $Wtb$ vertex structure using recent LHC data, combining multiple measurements to set improved limits on possible anomalous couplings, and also incorporates Tevatron results for a comprehensive analysis.

Contribution

It provides the first combined analysis of LHC and Tevatron data to set tighter constraints on anomalous $Wtb$ couplings using multiple observables.

Findings

New limits at 95% CL on real and imaginary parts of anomalous couplings.

Combination of LHC and Tevatron data improves sensitivity.

Updated measurements enhance constraints on the $Wtb$ vertex.

Abstract

The $Wtb$ vertex structure and the search for new anomalous couplings is studied using top quark measurements obtained at the LHC, for a centre-of-mass energy of 8 TeV. By combining the latest and most precise results on the single top quark production cross section and the measurements of the $W$-boson helicity fractions ($F_0$ and $F_L$), it is possible to set new limits, at 95% CL (confidence level), on the real and imaginary components of the new couplings. The combination of the LHC observables clearly improves the limits obtained when using the individual results alone. The updated measurements of the $W$-boson helicity fractions and the $s+t$-channels electroweak single top quark production, at the Tevatron, improve the LHC limits, when a world combination of all observables (LHC+Tevatron) is performed.