Diphoton decay for a $750$ GeV scalar boson in an $U(1)_{X}$ model

TL;DR

This paper explores a $750$ GeV scalar in a $U(1)_X$ model, explaining the diphoton excess observed at CERN-LHC through one-loop decays involving exotic quarks and charged Higgs, and considers dark matter implications.

Contribution

It introduces a $U(1)_X$ extension explaining the diphoton excess with detailed decay calculations and dark matter candidate integration.

Findings

Production cross section matches experimental data.

Decay via heavy quarks and charged Higgs is viable.

Dark matter candidate couples with the scalar.

Abstract

In the context of a nonuniversal and anomaly free $U(1)_{X}$ extension of the standard model, we examine the decay of a $750$GeV scalar singlet state, $\xi_{\chi}$, as a possible explanation of the observed diphoton excess announced by the ATLAS and CMS collaborations at CERN-LHC collider. One-loop decay to photons is allowed through three heavy singlet quarks and one charged Higgs boson into the loop. We obtain, for different width approximations and for masses of the exotic singlet quarks in the region $[900,\,3000]$ GeV, a production cross section $\sigma(pp\to\xi_{\chi}\to\gamma\gamma)$ compatible with ATLAS and CMS collaborations data. We also include another scalar singlet, $\sigma$, as a dark matter candidate that may couple with the 750 GeV scalar at tree level with production cross sections in agreement with ATLAS and CMS.