Diphoton excess and VV-scattering

TL;DR

This paper examines the implications of a 750 GeV resonance on VV scattering and effective interactions, finding that the large width and constraints from gauge boson interactions challenge the viability of certain models.

Contribution

It introduces a minimal effective interaction framework for the 750 GeV resonance and analyzes constraints from gauge boson scattering and resonance width.

Findings

Large width (~500 GeV) challenges the resonance interpretation.

Strong limits on vector-like fermion masses from gluon fusion production.

Effective model validity is constrained by VV scattering amplitudes.

Abstract

We consider minimal effective interactions of the 750 GeV mass resonance observed recently by ATLAS and CMS. Assuming a new scalar and gauge invariant effective interactions leads to non-trivial two particle scattering amplitudes with asymptotic gauge boson states. The longitudinally polarized $W\pm$ and $Z$ bosons interacting via dimension-five effective operators provide stringent constraints on the validity of the effective model. The large width found by ATLAS implying a bound of approximately 500 GeV already below the resonance, turns this scenario unlikely. For production mainly in gluon fusion we get an upper bound of $\sim 1.3$ TeV and strong limits on the masses of the underlying vector-like fermions are given.