<i>L<sub>α</sub></i> Line of Dark Positronium as a Nongravitational Detection of DM

Abstract

An attempt to predict the new atomic dark matter lines is done on the example of a dark lepton atompositronium. Its Layman-alpha line with the energy near 3 GeV may be observable if the appropriate conditions realize. For this we have studied a γ-ray excess in the Center of our Galaxy. In principle, this excess may be produced by the L α line of a dark positronium in the medium with Compton scattering. The possibility of observations of an annihilation line (E~300 TeV) of dark positronium is also predicted. Other proposals to observe the atomic dark matter are shortly described. Besides, H α line (1.3μ) of usual positronum must be observable in the direction on the Center of our Galaxy.

The dark components of the Universe are slowly clarified

“…One might probably expect the development of dark-medium spectroscopy and, as a consequence, the non gravitational detection of dark matter. Dark atoms, positronium, and monopolium, can play a key role here [66,67]. Therefore, it is important to recall the 'forgotten' magnetic charges that could form a magnetic atom, monopolium (g + g -), and even a kind of magnetic world at early cosmological epochs [67].…”