SUSY Implications from WIMP Annihilation into Scalars at the Galactic Center

TL;DR

This paper explores the possibility that dark matter annihilating into Higgs-pseudoscalar pairs could explain the gamma-ray excess observed at the galactic center, fitting data as well as traditional models and offering distinctive detection signals.

Contribution

It demonstrates that Higgs-pseudoscalar annihilation channels in the NMSSM can account for the gamma-ray excess while satisfying experimental constraints, providing a novel dark matter interpretation.

Findings

Higgs-pseudoscalar channel fits gamma-ray data as well as bottom-quark pairs.

Model regions satisfy relic density and experimental constraints.

Scalar decay into photons offers a potential detection signature.

Abstract

An excess in $\gamma$-rays emanating from the galactic centre has recently been observed in the Fermi-LAT data. We investigate the new exciting possibility of fitting the signal spectrum by dark matter annihilating dominantly to a Higgs-pseudoscalar pair. We show that the fit to the $\gamma$-ray excess for the Higgs-pseudoscalar channel can be just as good as for annihilation into bottom-quark pairs. This channel arises naturally in a full model such as the next-to-minimal supersymmetric Standard Model (NMSSM) and we find regions where dark matter relic density, the $\gamma$-ray signal and other experimental constraints, can all be satisfied simultaneously. Annihilation into scalar pairs allows for the possibility of detecting the Higgs or pseudoscalar decay into two photons, providing a smoking-gun signal of the model.