2019/01/31 by Yasaman Farzan, Meshkat Rajaee · 1 citation
Physics and Astronomy · #Annihilation #Astrophysics #Atomic and Subatomic Physics Research #Cosmology #Dark Matter and Cosmic Phenomena #Dark energy #Dark fluid #Dark matter #Electron #Hot dark matter #Isotropy #Light dark matter #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Positron #Quantum mechanics #Scalar field dark matter #hep-ph
paper · pdf · doi:10.1088/1475-7516/2019/04/040
arxiv created 2019/03/19 · openalex publication_date 2019/04/23 · arxiv updated 2019/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
The positron excess observed by PAMELA and then confirmed by AMS-02 has intrigued the particle physics community since 2008. Various dark matter decay and annihilation models have been built to explain the excess. However, the bounds from isotropic gamma ray disfavor the canonical dark matter decay scenario. We propose a solution to this excess based on the decay of dark matter particles into intermediate millicharged particles which can be trapped by the galactic magnetic field. The subsequent decay of the millicharged particles to electron positron in our vicinity can explain the excess. Since these particles diffuse out of the halo before decay, their contribution to the isotropic gamma ray background is expected to be much smaller than that in the canonic dark matter decay scenarios. We show that the model is testable by direct dark matter search experiments.