Higgs Spin Determination in the WW channel and beyond

TL;DR

This paper investigates how to distinguish a spin-2 Higgs-like resonance from the Standard Model Higgs (spin-0) at the LHC by analyzing production and decay distributions, proposing methods to identify the resonance's spin.

Contribution

It introduces a phenomenological model for a spin-2 resonance and demonstrates how certain distributions can differentiate it from a spin-0 Higgs, even when rates are similar.

Findings

Spin-2 can mimic SM Higgs rates in certain channels.

Differential distributions can distinguish spin-2 from spin-0.

Some observables are independent of spin-2 model parameters.

Abstract

After the discovery of the 126 GeV resonance at the LHC, the determination of its features, including its spin, is a very important ongoing task. In order to distinguish the two most likely spin hypotheses, spin-0 or spin-2, we study the phenomenology of a light Higgs-like spin-2 resonance produced in different gluon-fusion and vector-boson-fusion processes at the LHC. Starting from an effective model for the interaction of a spin-2 particle with the SM gauge bosons, we calculate cross sections and differential distributions within the Monte Carlo program Vbfnlo. We find that with specific model parameters such a spin-2 resonance can mimic SM Higgs rates and transverse-momentum distributions in $\gamma \gamma$, $WW$ and $ZZ$ decays, whereas several distributions allow to separate spin-2 from spin-0, independently of the spin-2 model parameters.