Sommerfeld Enhancement of DM Annihilation: Resonance Structure, Freeze-Out and CMB Spectral Bound

Abstract

In the last few years there has been some interest in WIMP Dark Matter models featuring a velocity dependent cross section through the Sommerfeld enhancement mechanism, which is a nonrelativistic effect due to massive bosons in the dark sector. In the first part of this article, we find analytic expressions for the boost factor for three different model potentials, the Coulomb potential, the spherical well and the spherical cone well and compare with the numerical solution of the Yukawa potential. We find that the resonance pattern of all the potentials can be cast into the same universal form. In the second part of the article we perform a detailed computation of the Dark Matter relic density for models having Sommerfeld enhancement by solving the Boltzmann equation numerically. We calculate the expected distortions of the CMB blackbody spectrum from WIMP annihilations and compare these to the bounds set by FIRAS. We conclude that only a small part of the parameter space can be ruled out by the FIRAS observations.

15 pages, 15 figures, version accepted by JCAP

References in corpus (14)

• Observation of an anomalous positron abundance in the cosmic radiation
• A Theory of Dark Matter
• Cosmology and Astrophysics of Minimal Dark Matter
• CMB Constraints on WIMP Annihilation: Energy Absorption During the Recombination Epoch
• Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01
• Gamma-ray and radio tests of the e+e- excess from DM annihilations
• Extended Anomalous Foreground Emission in the WMAP 3-Year Data
• Heavy Dark Matter Through the Higgs Portal
• Evidence Of Dark Matter Annihilations In The WMAP Haze
• Impact of dark matter decays and annihilations on reionization
• Contraints on radiative dark-matter decay from the cosmic microwave background
• Constraints on Dark Matter annihilations from reionization and heating of the intergalactic gas
• Gamma-ray continuum emission from the inner Galactic region as observed with INTEGRAL/SPI
• The Effects of Dark Matter Decay and Annihilation on the High-Redshift 21 cm Background

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• Teasing bits of information out of the CMB energy spectrum
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• Sensitivities of IceCube DeepCore Detector to Signatures of Low-Mass Dark Matter in the Galactic Halo
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