Galactic 511 keV line from MeV millicharged dark matter

Ji-Haeng Huh, Jihn E. Kim, Jong-Chul Park +1

We present a possible explanation of the recently observed 511 keV $\gamma$-ray anomaly with a new ``millicharged'' fermion. The new fermion is light ($\mathcal{O}(\mathrm{MeV})$) but has nev…