On the Heavy Relic Neutrino - Galactic Gamma Halo Connection

Abstract

A halo model with heavy relic neutrinos N belonging to a fourth generation and their annihilations in galactic halo may explain the recent evidence of diffused gamma (GeV) radiation around galactic plane. We considered a neutrino mass in the narrow range ($M_Z/2<m_N<M_Z$) and two main processes as source of gamma rays. A first one is ICS of ultrarelativistic electron pair on IR and optical galactic photons and a second due to prompt gammas by ${\pi }^0$ decay, leading to a gamma flux ($10^{-7}-10^{-6}/(c{m}^{2}ssr)$) comparable to EGRET detection. Our predictions are also compatible with the narrow window of neutrino mass $45GeV<m_N<60GeV$, required to explain the recent underground DAMA positive signals.

Comments: 7 pages, IDM Conference, Buxton Sept.1998