Indirect search for dark matter with micrOMEGAs2.4

TL;DR

The paper introduces a new indirect-detection module for micrOMEGAs 2.4 that enables end-to-end predictions of gamma-ray, positron, and antiproton signals from dark matter annihilation in a broad class of models with stable WIMPs. It combines automated annihilation cross-sections and spectra with sophisticated modeling of dark matter halos, line-of-sight photon fluxes, and a two-zone Galactic diffusion framework for charged-particle propagation, including solar modulation. Key contributions include polarization effects for vector bosons, full 2->3 photon-emission calculations with careful blotter for double-counting, and a flexible, user-extensible implementation of halo profiles and propagation parameters. The code is validated against other packages, demonstrates propagation-uncertainty impacts, and provides practical tools for rapid exploration of indirect-detection signals, significantly aiding interpretation of current and future astroparticle data.

Abstract

We present a new module of micrOMEGAs devoted to the computation of indirect signals from dark matter annihilation in any new model with a stable weakly interacting particle. The code provides the mass spectrum, cross-sections, relic density and exotic fluxes of gamma rays, positrons and antiprotons. The propagation of charged particles in the Galactic halo is handled with a new module that allows to easily modify the propagation parameters.

Figures (6)

• Figure 1: $dN/dE$ for positrons from DM annihilating into $W^+W^-$ with transversely polarised (full/black), longitudinally polarised (dash/pink) or unpolarised W's (full/blue), here $m_\chi=1$ TeV.
• Figure 2: a) Photon spectrum for the CMSSM point $m_0=70$ GeV, $M_{\frac{1}{2}}=250$ GeV, $A_0=-300$ GeV, $\tan\beta=10$ for $\chi\chi\rightarrow \tau^+\tau^-\gamma$ (black), $e^+e^-\gamma$ (black-dash), with photons from external legs from PYTHIA (FSR) (green-dash) and all contributions from 3-body final states (green-full). b) Photon spectrum for a MSSM point ($\mu=545 {\rm GeV}, M_1=500 {\rm GeV}, \tan\beta=20, M_A=2{\rm TeV}$ and $m_{\tilde{f}}=2.5{\rm TeV}$) with (full) and without (dash) the contributions from the three-body process $\chi\chi\rightarrow W^+W^-\gamma$
• Figure 3: $\gamma$-ray signal for Model 1(left) and Model 2(right) with micrOMEGAs and DarkSusy
• Figure 4: Positron signal for Model 1(left) and Model 2(right) with micrOMEGAs and DarkSusy. Here we have set $\delta=0.6$, $K_0=0.03607~{\rm kpc}^2/{\rm Myr}$, $L=4$ kpc and $V_C=10$ km/s.
• Figure 5: Antiproton signal for Model 1(left) and Model 2(right) with micrOMEGAs and DarkSusy. Same propagation parameters as above. Solar modulation is included with $\phi_F=320$ MV.