The shape of spins

TL;DR

This paper explores how event shape observables can be used to determine the spin quantum numbers of Higgs-like particles, enhancing our understanding of their properties and role in electroweak symmetry breaking.

Contribution

It introduces a novel approach using event shape observables to constrain the spin of Higgs-like particles based on their production mechanisms.

Findings

Event shape observables are sensitive to the spin of the particle.

The method can distinguish between different spin hypotheses.

Applicability extends to future Higgs-like particle discoveries.

Abstract

After the discovery of a Higgs-like particle at the LHC, the determination of its spin quantum numbers across different channels will be the next step in arriving at a more precise understanding of the new state and its role in electroweak symmetry breaking. Event shape observables have been shown to provide extremely sensitive observables for the discrimination of the scalar Higgs boson's CP quantum numbers as a consequence of the different radiation patterns of Higgs production via gluon fusion vs. weak boson fusion in the $pp\to X+2j$ selection. We show that a similar strategy serves to constrain the spin quantum numbers of the discovered particle as a function of the involved couplings. We also discuss the prospects of applying a similar strategy to future discoveries of Higgs-like particles.