Explaining the diphoton excess in Alternative Left-Right Symmetric Model

Abstract

We propose a possible explanation of the recent diphoton excess reported by ATLAS and CMS collaborations, at around 750 GeV diphoton invariant mass, within the framework of $E_6$ motivated Alternative Left-Right Symmetric Model (ALRSM), which is capable of addressing the $B$ decay anomalies in the flavor sector, the $eejj$ and $e$ missing $p_{T}jj$ excesses reported by CMS in run 1 of LHC and has the feature of high scale leptogenesis. We find that gluon-gluon fusion can give the observed production rate of the 750 GeV resonance, $\tilde{n}$, through a loop of scalar leptoquarks (${\tilde{h}}^{(c)}$) with mass below a few TeV range, while $\tilde{n}$ can subsequently decay into $\gamma \gamma$ final state via loops of ${\tilde{h}}^{(c)}$ and ${\tilde{E}}^{(c)}$. Interestingly, the ${\tilde{E}}^{(c)}$ loop can enhance the diphoton branching ratio significantly to successfully explain the observed cross section of the diphoton signal.

Comments: 10 pages, 7 figures, minor refinements, references added