Probing the anomalous triple gauge boson couplings in $e^+e^-\to W^+W^-$ using $W$ polarizations with polarized beams

TL;DR

This paper investigates the potential to detect anomalous triple gauge boson couplings in $e^+e^- o W^+W^-$ processes by analyzing $W$ boson polarization observables with polarized beams at future colliders, providing limits on new physics effects.

Contribution

It introduces a comprehensive analysis of $W$ polarization observables with polarized beams to constrain anomalous $W^+W^-V$ couplings using effective field theory and MCMC methods.

Findings

Best limits obtained with $( ext{polarization}) = ( ext{±}0.8, ext{∓}0.6)$

Limits are estimated for different collider luminosities

Polarized beams significantly improve sensitivity to anomalous couplings

Abstract

We study the anomalous $W^+W^-V$ ($V=\gamma,Z$) couplings in $e^+e^-\to W^+W^-$ using the complete set of polarization observables of $W$ boson with longitudinally polarized electron ($e^-$) and positron ($e^+$) beams. For the effective $W^+W^-V$ couplings, we use the most general Lorentz invariant form factor parametrization as well as $SU(2)\times U(1)$ invariant dimension-$6$ effective operators. We estimate simultaneous limits on the anomalous couplings using the Markov-Chain--Monte-Carlo (MCMC) method for an $e^+e^-$ collider running at center of mass energy of $\sqrt{s}=500$ GeV and the integrated luminosity of ${\cal L}=100$ fb$^{-1}$, $3.2$ ab$^{-1}$ and $4$ ab$^{-1}$. The best limits on the anomalous couplings are obtained for $e^-$ and $e^+$ polarization being $(\pm 0.8,\mp 0.6)$ for both $100$ fb$^{-1}$ and $3.2$ ab$^{-1}$ of luminosity.