The Diphoton and Diboson Excesses in a Left-Right Symmetric Theory of Dark Matter

TL;DR

This paper proposes a minimal left-right symmetric model that explains recent diphoton and diboson excesses at the LHC while also providing a viable dark matter candidate, predicting distinctive missing energy signatures.

Contribution

It introduces a novel minimal extension of left-right symmetry that simultaneously accounts for collider excesses and dark matter relic abundance.

Findings

The 750 GeV neutral right-handed Higgs triplet explains the diphoton excess.

Interactions with dark matter multiplets dominate production and decay.

The model predicts missing energy signatures in diphoton events.

Abstract

We explore the possibility that the recently reported diphoton excess at ATLAS and CMS can be accommodated within a minimal extension of a left-right symmetric model. Our setup is able to simultaneously explain the Run 2 diphoton and Run 1 diboson excesses, while providing a standard thermal freeze-out of weak-scale dark matter. In this scenario, the 750 GeV neutral right-handed Higgs triplet is responsible for the diphoton excess. Interactions of this state with the neutral and charged components of dark matter multiplets provide the dominant mechanisms for production and decay. A striking signature of this model is the additional presence of missing energy in the diphoton channel.