New vector bosons and the diphoton excess

TL;DR

This paper explores how new vector bosons from a symmetry-breaking sector could explain the 750 GeV diphoton excess, linking it to potential new physics involving colored vectors and connections to other anomalies.

Contribution

It proposes a simplified model with a scalar and vector bosons to explain the diphoton excess, considering both colored and non-colored vectors and their implications.

Findings

A scalar coupled to photons via loops of charged vectors can explain the excess.

Colored vectors can generate gluon couplings, enabling a complete explanation.

Connections between diphoton, diboson, and top quark anomalies are discussed.

Abstract

We consider the possibility that the recently observed diphoton excess at $\sim 750$ GeV can be explained by the decay of a scalar particle ($\varphi$) to photons. If the scalar is the remnant of a symmetry-breaking sector of some new gauge symmetry, its coupling to photons can be generated by loops of the charged massive vectors of the broken symmetry. If these new $W^\prime$ vector bosons carry color, they can also generate an effective coupling to gluons. In this case the diphoton excess could be entirely explained in a simplified model containing just $\varphi$ and $W^\prime$. On the other hand if $W^{\prime}$ does not carry color, we show that, provided additional colored particles exist to generate the required $\varphi$ to gluon coupling, the diphoton excess could be explained by the same $W^{\prime}$ commonly invoked to explain the diboson excess at $\sim 2$ TeV. We also explore possible connections between the diphoton and diboson excesses with the anomalous $t\bar{t}$ forward-backward asymmetry.