5. Theoretical Physics (CSN4)

(H)ALPing the 511 keV line: A thermal DM interpretation of the 511 keV emission

by Giulio Marino (Istituto Nazionale di Fisica Nucleare)

Europe/Rome
Aula Seminari (Laboratori Nazionali di Frascati)

Aula Seminari

Laboratori Nazionali di Frascati

Description

 

We propose a novel framework where MeV-scale Dirac Dark Matter annihilates into axion-like particles, providing a natural explanation for the 511 keV gamma-ray line observed in the Galactic Center. The relic abundance is determined by p-wave annihilation into two axion-like particles, while s-wave annihilation into three axion-like particles, decaying into e+e− pairs, accounts for the line intensity. Remarkably, this model, assuming a standard Navarro-Frenk-White profile, reproduces the observed emission morphology, satisfies in-flight annihilation and cosmological bounds, and achieves the correct relic density, offering a compelling resolution to this longstanding anomaly.