Galactic Center Gamma Ray Excess and Higgs Boson(s)

TL;DR

This paper investigates the gamma ray excess at the Galactic Center, proposing a dark matter model involving a pseudoscalar mediator that interacts with the Standard Model, and analyzes its experimental constraints.

Contribution

It introduces a renormalizable dark matter model with a pseudoscalar mediator mixing with the Higgs sector to explain the gamma ray excess.

Findings

The model fits the gamma ray spectrum with 30 GeV dark matter annihilation.

Constraints from direct detection, Higgs decays, and B meson decays are analyzed.

The proposed model remains viable within current experimental bounds.

Abstract

There is evidence for an excess of gamma rays with $O({\rm GeV})$ energy coming from the Galactic Center in data from the Fermi Telescope. The spectrum of the excess is well fit by 30 GeV dark matter annihilating into a pair of $b$ quarks with a cross section expected from a thermal relic. For an explanation of this excess, we study a renormalizable model where dark matter couples to the SM via a pseudoscalar that mixes with the $CP$-odd Higgs boson of a Two HIggs Doublet Model. We report the constraints on this model from direct detection, Higgs decays, and rare $B$ meson decays.