W boson polarization as a measure of gauge-Higgs anomalous couplings at the LHC

TL;DR

This paper proposes using W boson polarization measurements in associated W-Higgs production at the LHC to constrain anomalous WWH couplings, providing a new method to probe deviations from the Standard Model.

Contribution

It introduces a calculation of the W boson spin density matrix including anomalous couplings and demonstrates how angular asymmetries can measure these couplings at the LHC.

Findings

Angular asymmetries can effectively measure W boson polarization.

Limits on anomalous WWH couplings can be estimated for future LHC runs.

Method provides a new way to test gauge-Higgs interactions.

Abstract

We show how the $W$ boson polarization in the process of associated $W^{\pm}H$ production at the Large Hadron Collider (LHC) can be used to constrain anomalous $WWH$ couplings. We first calculate the spin density matrix for the $W$ to linear order in the anomalous couplings, which are assumed to be small. We then evaluate angular asymmetries in the decay distributions of leptons produced in the decay of the $W$ and show how they can be used to measure the individual elements of the polarization tensor. We estimate the limits that can be placed on the anomalous $WWH$ couplings at a future run of the LHC.