Resonant Diphoton Phenomenology Simplified

TL;DR

This paper introduces a comprehensive, model-independent framework for analyzing resonant diphoton signals at hadron colliders, enabling detailed characterization of new particles and their properties based on experimental data.

Contribution

It provides a general theoretical framework and benchmark scenarios for interpreting diphoton resonance data, including methods to determine properties like spin and CP-parity after discovery.

Findings

Characterized the 750 GeV diphoton excess using the framework.

Identified how to infer resonance spin and production mode from diphoton distributions.

Discussed methods to partially determine CP-parity, especially for J≥2.

Abstract

A framework is proposed to describe resonant diphoton phenomenology at hadron colliders in full generality. It can be employed for a comprehensive model-independent interpretation of the experimental data. Within the general framework, few benchmark scenarios are defined as representative of the various phenomenological options and/or of motivated new physics scenarios. Their usage is illustrated by performing a characterization of the 750 GeV excess, based on a recast of available experimental results. We also perform an assessment of which properties of the resonance could be inferred, after discovery, by a careful experimental study of the diphoton distributions. These include the spin J of the new particle and its dominant production mode. Partial information on its CP-parity can also be obtained, but only for $J\geq2$. The complete determination of the resonance CP properties requires studying the pattern of the initial state radiation that accompanies the resonant diphoton production.