Knocking on New Physics' door with a Scalar Resonance

TL;DR

This paper explores the possibility that a new scalar resonance at 750 GeV, observed as a diphoton excess, could be produced via gluon fusion, requiring new colored and charged particles, and discusses various theoretical interpretations.

Contribution

It provides a model-independent framework for the 750 GeV diphoton excess and analyzes the implications of gluon fusion production for new particle requirements.

Findings

The excess can be explained by a scalar produced in gluon fusion.

Additional colored and charged particles are necessary for this production mode.

Various theoretical models can accommodate the resonance, including singlet scalars and composite Higgs scenarios.

Abstract

We speculate about the origin of the recent excess at ~750 GeV in diphoton resonance searches observed by the ATLAS and CMS experiments using the first 13 TeV data. Its interpretation as a new scalar resonance produced in gluon fusion and decaying to photons is consistent with all relevant exclusion bounds from the 8 TeV LHC run. We provide a simple phenomenological framework to parametrize the properties of the new resonance and show in a model-independent way that, if the scalar is produced in gluon fusion, additional new colored and charged particles are required. Finally, we discuss some interpretations in various concrete setups, such as a singlet (pseudo-) scalar, composite Higgs, and the MSSM.