Studying dark matter with MadDM: lines and loops

TL;DR

This paper introduces new features in MadDM, enabling automated calculations of loop-induced dark matter annihilation processes into photons, which are crucial for indirect detection via gamma-ray lines, and applies this to constrain models like the Inert Doublet Model.

Contribution

The paper presents the latest version of MadDM with automated loop process computations for dark matter annihilation into photons, enhancing indirect detection analysis capabilities.

Findings

MadDM can now compute loop-induced gamma-ray lines.

Constraints on dark matter models from gamma-ray line searches.

Application to the Inert Doublet Model parameter space.

Abstract

Automated tools for the computation of amplitudes and cross sections have become the backbone of phenomenological studies beyond the standard model. We present the latest developments in MadDM, a calculator of dark-matter observables based on MadGraph5_aMC@NLO. The new version enables the fully automated computation of loop-induced annihilation processes, relevant for indirect detection of dark matter. Of particular interest is the direct annihilation into photons, $\gamma \gamma,\, \gamma X$. These processes lead to monochromatic gamma-ray lines that are smoking-gun signatures for dark-matter annihilation in our Galaxy. MadDM computes the predictions for the expected photon fluxes near Earth and derives constraints from the gamma-ray line searches by Fermi-LAT and HESS. As an application, we present the implications for the parameter space of the Inert Doublet Model.