Multi-step production of a diphoton resonance

TL;DR

This paper proposes two distinct weakly-coupled models for producing a diphoton resonance at the LHC, exploring different initial states and decay chains to help identify the underlying production mechanism.

Contribution

It introduces two novel renormalizable models for diphoton resonance production, differing in initial states and decay pathways, aiding in experimental differentiation.

Findings

Kinematic distributions can distinguish models from direct gluon fusion production.

Models involve scalar decay and Z' cascade decay mechanisms.

Provides theoretical frameworks for future experimental tests.

Abstract

Among the questions that would be raised by the observation of a new resonance at the LHC, particularly pressing are those concerning the production mechanism: What is the initial state? Is the resonance produced independently or in association with other particles? Here we present two weakly-coupled renormalizable models for production of a diphoton resonance that differ in both their initial and final states. In one model, a scalar particle produced through gluon fusion decays into a diphoton particle and a light, long-lived pseudoscalar. In another model, a $Z'$ boson produced from the annihilation of a strange-antistrange quark pair undergoes a cascade decay that leads to a diphoton particle and two sterile neutrinos. Various kinematic distributions may differentiate these models from the canonical model where a diphoton particle is directly produced in gluon fusion.