Internal Bremsstrahlung Signature of Real Scalar Dark Matter and Consistency with Thermal Relic Density

TL;DR

This paper explores a simple dark matter model with Yukawa interactions that can explain the gamma-ray excess from the galactic center while remaining consistent with the observed relic density.

Contribution

It introduces a Yukawa interaction model for scalar dark matter that aligns with gamma-ray signals and thermal relic constraints.

Findings

Identifies parameter space compatible with gamma-ray excess

Demonstrates consistency with thermal relic density

Provides predictions for dark matter annihilation signals

Abstract

A gamma-ray excess from the galactic center consistent with line emission around 130 GeV was recently found in the Fermi-LAT data. Although the Fermi-LAT Collaboration has not confirmed its significance, such a signal would be a clear signature of Dark Matter annihilation. Until now, there have been many attempts to explain the excess by Dark Matter. However these efforts tend to give too-small cross sections into photons if consistency with the correct thermal relic density of Dark Matter is required. In this letter, we consider a simple Yukawa interaction that can be compatible with both aspects and show which parameters are favored.