Di-photon excess at LHC and the gamma ray excess at the Galactic Centre

TL;DR

This paper explores whether a 750 GeV pseudoscalar mediator can simultaneously explain the 750 GeV di-photon excess at the LHC and the gamma-ray excess at the Galactic Centre, analyzing experimental constraints and model viability.

Contribution

It demonstrates the compatibility of the LHC and Galactic Centre signals within an effective pseudoscalar mediator model, considering experimental constraints.

Findings

The model can explain both excesses simultaneously.

LHC mono-jet and Fermi LAT data significantly restrict the parameter space.

Cosmic antiproton flux measurements may further impact model viability.

Abstract

Motivated by the recent indications for a 750 GeV resonance in the di-photon final state at the LHC, in this work we analyse the compatibility of the excess with the broad photon excess detected at the Galactic Centre. Intriguingly, by analysing the parameter space of an effective models where a 750 GeV pseudoscalar particles mediates the interaction between the Standard Model and a scalar dark sector, we prove the compatibility of the two signals. We show, however, that the LHC mono-jet searches and the Fermi LAT measurements strongly limit the viable parameter space. We comment on the possible impact of cosmic antiproton flux measurement by the AMS-02 experiment.