Hidden confining world on the 750 GeV diphoton excess

Abstract

We explain the recent diphoton excesses around 750 GeV by both ATLAS and CMS as a singlet scalar $\mathrm{\ensuremath{\Phi}}$ which couples to SM gluon and neutral gauge bosons only through higher-dimensional operators. A natural explanation is that $\mathrm{\ensuremath{\Phi}}$ 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 metastable colored 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.