Multi-Photon Signals from Composite Models at LHC

TL;DR

This paper investigates collider signals of composite scalars from certain models, highlighting their distinctive multi-photon signatures at the LHC and assessing discovery prospects and spin measurement methods.

Contribution

It provides the first detailed analysis of multi-photon signals from composite scalars in little Higgs and vectorlike confinement models at the LHC.

Findings

LHC can discover these models with 30 fb$^{-1}$ at 14 TeV.

Early discovery possible at 7 TeV in some parameter regions.

Methods to measure the spin of the particles are discussed.

Abstract

We analyze the collider signals of composite scalars that emerge in certain little Higgs models and models of vectorlike confinement. Similar to the decay of the pion into photon pairs, these scalars mainly decay through anomaly-induced interactions into electroweak gauge bosons, leading to a distinct signal with three or more photons in the final state. We study the standard model backgrounds for these signals, and find that the LHC can discover these models over a large range of parameter space with 30 fb$^{-1}$ at 14 TeV. An early discovery at the current 7 TeV run is possible in some regions of parameter space. We also discuss possibilities to measure the spin of the particles in the $\gamma \gamma $ and $Z\gamma $ decay channels.