Higgs spin determination in the WW channel and beyond

Jessica Frank,Dieter Zeppenfeld,Michael Rauch

doi:10.1140/epjc/s10052-014-2918-z

Jessica Frank, Dieter Zeppenfeld + Show 1 more

Open Access

https://doi.org/10.1140/epjc/s10052-014-2918-z

Copy DOI

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.

Highlights

A new, Higgs-like resonance with a mass of about 126 GeV has been discovered by the LHC experiments ATLAS [1] and CMS [2]
We focus on the phenomenology of spin-2 resonances in the W W channel produced in gluon fusion or vectorboson fusion (VBF) and discuss differential distributions, which can be useful to distinguish between a Standard Model (SM) Higgs and a spin-2 resonance
Focusing on the W W decay channel, we present differential distributions which can be useful for a spin determination and study the impact of spin-0 and spin-2 model parameters and of next-toleading order (NLO) QCD corrections in the VBF mode

Summary

Introduction

A new, Higgs-like resonance with a mass of about 126 GeV has been discovered by the LHC experiments ATLAS [1] and CMS [2]. Whereas in a previous analysis [23] we have studied the phenomenology of spin-2 resonances in the VBF photon pair-production mode, we present cross sections for spin-2 resonances in all these processes and show that with a suitable choice of model parameters, spin-2 resonances can approximately reproduce SM Higgs cross sections in all the different channels. Our calculations are performed with the Monte Carlo program Vbfnlo [45,46,47] by using an effective Lagrangian approach for a spin-2 (or spin-0) field interacting with the SM gauge bosons.

Spin-2 and spin-0 parametrization

Elements of the calculation

Input parameters and selection cuts

Results

Conclusions