Scalar Explanation of Diphoton Excess at LHC

TL;DR

This paper proposes a vector-like quark model with a 750 GeV scalar or pseudo-scalar to explain the diphoton excess observed at the LHC, showing it can fit data from 13 TeV and 8 TeV runs.

Contribution

It introduces a specific vector-like quark model with exotic charges that accounts for the diphoton excess while remaining consistent with previous LHC data.

Findings

Model explains the diphoton excess at 13 TeV LHC.

Model remains consistent with 8 TeV LHC data.

Scalar production via gluon fusion with loop decays to dibosons.

Abstract

Inspired by the diphoton signal excess observed in the latest data of 13 TeV LHC, we consider either a 750 GeV real scalar or pseudo-scalar responsible for this anomaly. We propose a concrete vector-like quark model, in which the vector-like fermion pairs directly couple to this scalar via Yukawa interaction. For this setting the scalar is mainly produced via gluon fusion, then decays at the one-loop level to SM diboson channels $gg, \gamma\gamma, ZZ, WW$. We show that for the vector-like fermion pairs with exotic electric charges, such model can account for the diphoton excess and is consistent with the data of 8 TeV LHC simultaneously in the context of perturbative analysis.