A hidden confining world on the 750 GeV diphoton excess

TL;DR

This paper proposes a model where a singlet scalar explains the 750 GeV diphoton excess via higher dimensional operators, involving a hidden strong dynamics that could also produce dark matter candidates.

Contribution

It introduces a pseudo-Nambu-Goldstone boson framework with hidden strong dynamics to explain the diphoton excess and predicts new decay channels and dark matter candidates.

Findings

The scalar couples to SM gauge bosons through higher dimensional operators.

Predicted decay modes include two SM gauge bosons and potential meta-stable colored states.

The model suggests a dark matter candidate from the lightest baryon in the hidden sector.

Abstract

We explain the recent diphoton excesses around $750$ GeV by both ATLAS and CMS as a singlet scalar $\Phi$ which couples to SM gluon and neutral gauge bosons only through higher dimensional operators. A natural explanation is that $\Phi$ is a pseudo-Nambu-Goldstone boson (pNGB) which receives parity violation through anomaly if there exists a hidden strong dynamics. The singlet and other light pNGBs will decay into two SM gauge bosons and even serves as the meta-stable coloured states which can be probed in the future. By accurately measuring their relative decay and the total production rate in the future, we will learn the underlying strong dynamics parameter. The lightest baryon in this confining theory could serve as a viable dark matter candidate.